Chapter - 26

Out Board Seamanship

You could say that buying an outboard boat and motor is something like getting married. You have to be certain the two will get along together. The purchaser of an inboard is not forced to think through this problem. The match has already been made by the builder who has installed the engine in the boat. But the purchaser of an outboard has to do his own pairing. The boat and motor come separate. Indeed, he can purchase the boat from one dealer and the motor from another.

For the new boatman especially, it is a deranging problem to sift through the torn bag of bright colored, bold-worded, attention-grabbing brochures, leaflets, throw-aways picked off the booths at some boat show—to disengage himself from the pouring of claims, counterclaims, contradictions, streaming from typewriters and drawing boards in public relations and advertising offices—to stand above the flooding verbiage of "bigger and better," "mostest," and "the fastest"—to decide what he wants a boat for, and on the basis of competent advice what he wants in a boat.

The value of an outboard as a status symbol has no relation to its value on the water. So use some of that old-fashioned American sense of practicality. Answer these questions. Is it sound? Solid? Will it do the job?

Now, if it is speed you desire—and certainly the sensation of a planing hull streaking over the water is one of the pleasures accruing from outboards—be sure to acquire the boat and motor and combination thereof that will give you maximum, safe performance. However, do not be like the fellow who hurries to a dealer in the fall to trade in for the latest highest horsepowered motor. Put that on the transom of the eager beaver's current boat, and it is likely to squat at the berth, bow pointed strangely into the air as though poised for celestial flight to Mars, while the stern is being urged toward that well-known locker of Davy Jones. To put this another way: because a boat goes 15 mph with a 72 hp motor, does not mean it will go 30 mph with a 15 hp motor. Indeed, this practice can be dangerous, since the big motor tends to pull the stern downward. Of course, the reverse is true. You can attach too small a motor. An underpowered boat will perform sluggishly.

Save yourself from having to learn this from hard experience. Consult competent dealers and others who are experienced. In many instances, you can obtain reliable advice from the OBC capacity recommendation plate on a boat. The letters OBC signify the Outboard Boating Club of America with headquarters at 307 North Michigan Avenue, Chicago 1, Illinois. The OBC represents the outboard boatman. It promotes the development of marinas and service facilities for outboards, provides outboard cruising information, encourages the organization of local outboard clubs, and even issues insurance policies for outboards. One of its activities is the products standards program.

The recommendation capacity plate comes under the latter program. The plate is attached to the hull and tells the maximum horsepower and load in pounds (including passengers) the boat is designed to carry. If the boat lacks a plate, ask the dealer for recommendations, or request them direct from the manufacturer. Following these recommendations will help you avoid two common causes of accidents : overpowering and overloading.

Types Of Boats

Matching the boat and motor is one thing. Getting the combination that will correspond to your boating needs and desires is another. There is a Christmas tree array of boats to choose from: everything from little boats that can be transported on tops of cars and which can take up to 4 hp motors to speedy craft that can be equipped with the highest horsepower motors available. There are prams, dinghies, skiffs, canoes, runabouts, and utilities. There are special outboards like Sea Sleds and houseboats. The 1950's saw the popularization of the outboard cruiser.

Your first question. What are you going to use your outboard boat for? Fishing? Family cruising? Skiing? Beach picnics? Skin-diving? Camping? Photography afloat? Or just plain thrill rides? The fisherman does not want to try trolling with a hydroplane designed to zoom at 50 mph.

Your second question. In what kind of water are you going to use the boat? Salt water or fresh? Large open bays and lakes, or shallow and more sheltered rivers and lakes ? The shallow-draft and fast boat you drive on more placid, enclosed bodies of water may not stand you in good stead on open rough waters.
 
Here is a brief rundown on the types of outboards available. There are two basic types of hulls: displacement and planing. Displacement boats plow through the water; planing hulls lift and skim over the surface.

Flat bottom (displacement type). Usually rowboats or skiffs 14' to 18' used for fishing or utility purposes on shallow streams and small, protected lakes. Design characterized by straight lines and boxy construction. They are not fast. They are generally heavy and roomy. (Some light flat bottom boats plane and are fast.)
Round-bottom (displacement) hulls. Dinghies, tenders, car-top boats, occasionally runabouts 12' to 18'. These hulls are often more easily driven and maneuvered than the flat-bottom craft. (Many fast light round bottom boats will also plane.)

Hydroplane or planing hulls. Generally used for competitive racing boats. The bottom, which is flat, is usually "stepped" (or divided into two levels) about amidships. The resultant notch reduces the wetted surface and increases speed.

Vee-bottom hulls. These are commonly used, especially for runabouts, utilities, and cruisers. The forward undersection of a Vee-bottom boat is usually a deep "V" in shape. This flattens towards amidships, until at the stern the bottom of the boat is usually broad and flat.

In effect, a utility and a runabout are practically interchangeable. They function about the same, are about the same size, use about the same horsepower, etc. However, the runabout is generally considered to be a bit faster and more luxuriously equipped than the utility of comparable size.

Here are a couple of helpful tips in buying a boat. Take the boat and motor for a trial run to see how they operate in combination. And never buy a boat, especially a used boat, when it is in the water. Have it taken out so it can be checked to see that frames, planking and fastenings are in good condition. If you are inexperienced, have a competent person ride with you and inspect the boat and motor.

Under The Law

Make sure you have complied with Federal, state and local laws. You will have to check laws of your community yourself. The OBC has a round-up of state laws. Federal laws are obtainable from a Coast Guard office.

Check to see if your boat should be numbered under the Federal Boating Act of 1958. All boats, regardless of length, that carry a 10 hp or larger motor must be numbered and in some states a number will be required even if the motor is less than 10 hp. In some cases the states have assumed the numbering functions. In others they are still in the hands of the Federal authorities.

Required Equipment

Make sure your boat carries all the equipment required by law. These requirements have been drafted to insure the safety of you, your passengers and the people in other boats around. It is imperative that you heed the law.
Do you realize that if everyone in a boat actually wore a life-saving device, that the death rate from boating accidents conceivably could be reduced 97 per cent? That is a startling figure. But statistics have shown that 97 per cent of the deaths resulting from boating accidents have been due to drowning.

You never can take safety for granted when in a boat—no matter how calm the water and still the day. The slightest accident could result in tragedy. Remember, what might be a dented fender in an automobile mishap, could be a person overboard in a boating mishap.

The skipper can use some discretion as to the type of life-saving equipment provided it meets legal requirements. It can consist of Coast Guard approved life jackets, buoyant cushions, or ring buoys. The OBC recommends life jackets for children and non-swimmers. These persons at least, along with babies, should wear life preservers at all times when aboard.

The skipper should make sure his passengers know how to use these devices. If they do not know, the skipper should give instruction. For instance, OBC recommends that if a person falls overboard and is thrown a buoyant cushion, he should slip his left arm through one of the loops. Then he puts his right leg through the other. (This process is reversed in the case of a left-handed person.) He holds the cushion against his chest with the left (or right, if that is the case) arm. Thus, the other arm and both legs are left free for swimming. However, if the water is rough, it may be easier to slip the arms through the straps as one dons a vest.

If your outboard has any kind of closed space (even though the hull be of generally open construction) you must carry a fire extinguisher. Do not be like the fellow who stows it carefully, then cannot find it when needed. Put it where you can grab it quickly. Amidships is a good place to keep the extinguisher.

There has been some confusion regarding the Coast Guard's new policy regarding fire extinguishers of the vaporizing liquid type, particularly carbon tetrachloride. This type extinguisher can no longer be installed on boats. However, those manufactured before December, 1958 and already installed and serviceable, can be used until January, 1962.

EQUIPMENT CHECK LIST FOR SKIPPER, CREW AND BOAT

Power:

Two 4O-hp Evinrude Lark Us, one with generator

Set of Simplex engine controls

Evinrude cruiser-fuel system

Two Columbian Bronze JM aluminum propellers, four bladed

Seatronics tachometer with throw-switch for both motors

Curtiss·Wright Star*Port steerer

Two 12-volt batteries

Two Burroughs battery boxes

Navigation:

Coast & Geodetic Survey charts

Pair of “12 lucite parallel rules

Pair of dividers

Pair of 7 x 50 binoculars

Lead line

United States Coast Pilot 3

Piloting, Seamanship and Small

Boat Handling Inland Waterway Guide, Northern

Edition

Petroleum company cruising charts

Wilfrid O. White's Corsair compass Light List

MoToR BOATING'S log book Plenty of paper, pens and pencils Watch with second hand

G»ounp tackle:

8-pound standard Danforth anchor 12-pound Hi-Tensile Danforth anchor

Two 100-foot lengths of a" nylon Two 5-foot lengths of ¾" galvanized chain      `

Four ¼" galvanized shackles

Four a" galvanized thimbles .
 
Required:

Falcon freon-type air horn with refill Kidde 2½-pound dry chemical fire extinguisher Two Coast Guard-approved life jackets Two Coast Guard-approved buoyant cushions Properly functioning running lights with spare bulbs, fuses State registration certificate State numbers properly mounted

Safety Equipment:

Sentinel first aid kit Flares, day and night Longport electric bilge pump 12-foot oar Portable radio Manual bilge pump

Boat hook

Two spare propellers

Several spare cotter pins for propeller hubs

Hand flashlight

Hand lantern

Two extra spark plugs

Mooring:

Four 25-foot lengths of a" nylon Three plastic-foam fenders

Six Wilcox-Crittenden fender locks

Clothing:

Two pair of Hodgman Rubber Co. foul-weather suits

Two pair of Sperry Topsider's canvas oxfords

Two ski parkas

Sun glasses
Towels

Warm socks

Chinos

Bathing suits

Underwear

Sweaters

Caps

Shirts, warm and summery

Set of thermal underwear

Gloves

Sleeping:

Sheets Pillows

Warm blankets Alarm clock

Tools:

Fiberglass tool-tackle box Several sharp pen knives Set of regular screwdrivers Set of Phillips screwdrivers

Dumas' interchangeable-headed hammer

Regular pliers

Long-nosed pliers

Boat tape

Spark plug remover and gauge

Sandpaper and emery cloth

Various types of oil and graphite

Assortment of screws and bolts with nuts and washers
Set of socket wrenches, ratchet type

Plastic wood

Waterproof sealer

Extra fuses

Extra "keys" for water and fuel tanks

Galley:

Commodore's stainless steel ice pick

Can of alcohol

Cigarettes

Matches

Lighter fluid

Copper wool

Soap

Soap dish

Assorted pots and pans

Spice containers

Plastic plates and cups

Stainless-steel eating utensils

Aluminum foil

Can and bottle opener

Stainless steel cleaner

Head:

Toilet paper

Comb Hair tonic

Sun tan lotion

Tooth brush

Tooth paste

Insect repellent

Miscellaneous¡

Swab

Bucket

Sponges

Camera

Fibs

Plastic wrap for camera

Bilge cleaner

Ash trays
 
All the equipment listed above is carried aboard one particular boat, a 22-foot express cruiser powered by two outboard motors. Because the boat is representative of a great many craft in use today, the list serves as an excellent reference for those seeking an equipment guide. Brand names listed here, of course, are not the only makes that will do the jobs called for—but each name given can safely be said to be among the best.
 
Even if you do not plan to use your outboard at night, sometime you may have no choice. So your boat should carry the lights prescribed by law. Two lights are required for outboards up to 26': a combination red and green light in the bow and a white stern light that is visible all around the horizon (360 degrees) for at least two miles. If you have a cruiser, you can mount the stern light on the after end of the cabin top.

Outboards between 16 and 26 feet must carry a horn, or a hand, mouth or power whistle that can set vibration going in the ear of someone a half mile away. This is used both for passing whistle signals and fog signals.

Recommended Equipment

The equipment required by law does not cover all that is required by boating's exigencies. The law says nothing about carrying an extra propeller. But if your boat should slam into debris, disabling the propeller, the situation would demand another propeller. You should carry an extra approved tank full of gas in case your boat has to go farther than you had planned. The boat should carry an anchor with at least 100 feet of a" nylon line or 2" manila. Maybe you can see straight, but only the compass can insure your boat staying on course if you are cruising in thick weather. You should have at least three fenders to protect rail and topsides when alongside a float, pier or another boat. A tool kit should contain pliers, screwdriver, patented wrench, shear pins, cotter pins, extra spark plugs. Carry a first aid kit, flashlight and, if far from shore, distress flares or smoke signals.

Although it might sound backward—carry a pair of oars (or, better, one long one). What man has put together—in the way of pistons, pins, shafts, rods, etc.—can go asunder as anyone can testify who has been caught miles from port with only his hands for motive power. Anyway, an oar is generally handy. You can use it to work the bow around if you get aground, for maneuvering in crowded mooring areas, and for pulling to safety a person who has fallen overboard.

On The Road

Since the trailer has become such an integral part of the outboard boating picture—and of the highway, also—this section will discuss "roadmanship." It was not so long ago that the word "trailer" evoked the image of a contraption, usually homemade, being pulled on a couple of wheels. It was not until 1939 that the first professionally designed, mass-produced small boat trailers were wheeled out of the factory. Today, like so many other things, they are "scientifically" produced. Constantly, they are appearing with innovations, improvements and, of course, gimmicks. They come variously equipped with electric winches, vertically adjustable keel rollers, and "finger tip" controls for loading and launching. About all the hard-working skipper has to do is to lie on the bank and let his two-year-old son do all the work with his own two little fingers.

Match Trailer To The Boat

But the essential problem remains—to match your boat and motor to the proper trailer.

You have got to have a trailer that will carry the weight—not only of the boat, but also of the gear you may stow in the boat when transporting it, and the motor or motors you probably will carry on the transom (which can usually be done in trailering). So a rule of thumb is this. When considering a trailer, check the manufacturer's recommended load capacity. This should be listed on a plate fixed to the trailer. If the actual weight of the boat (some manufacturers underestimate the weights of their models, so check carefully) is within 100 pounds of the trailer's recommended weight capacity, buy the next largest trailer model. But do not mislead yourself and get a huge trailer to carry a modest-size boat. For the trailer must fit the hull.

Remember that a trailer is actually an unnatural place for a boat. So you have to "baby" it all you can. Make the trailer bed as comfortable as possible. See that it fits the contours of the hull. Plenty of padding and bracing is needed. Treat the boat right on the trailer and it will reciprocate in the water. There will not be a "sag" in the hull or a "hook" (in the stern from too short a trailer) to slow the boat.

One type of trailer rests the boat on a boom or a series of adjustable rollers. This trailer is often referred to as the full-keel support type. Another kind supports the boat by means of cradles, there often being one cradle at the front and one at the rear. However, a boat kept too long on such a cradle—or kept over the winter on it—tends to "sag."

If you carry the motor, or motors, on the transom, you need adequate support for this. The rear member of the trailer should be located directly below. It should have a wide supporting area, so the weight will not be concentrated on a narrow member. In some instances it may be necessary to relocate the trailer wheels closer to the rear. This would provide more direct support and at the same time keep the load weight heavier—by some 50 to 60 pounds—at the front of the trailer.

With the center of gravity located somewhat forward, towing will be smoother. Also, when you disconnect the trailer you will be able to walk away with it—even when loaded. So, when loading gear aboard, distribute it so that this balance will not be disturbed.

Clamp the motor tight to the boat. To prevent the motor from tilting forward because of sudden stops, secure its lower unit to the stern of the boat or to the trailer frame. Cover the motor to stern bracket to keep out dust. Remove cover at journey's end so condensation inside does not hurt motor.

A bumper hitch will be alright if you pull a light rig. But for the heavier job, use a hitch that fits directly to the frame of the car—a frame hitch. Although the law may not require it, use safety hitch chains anyway. They are excellent precautions.

Trailer Laws Vary

Remember, the laws covering trailers vary among the states. For instance, your trailer may lack directional signals (although it is good to have them). This might not evoke even so much as a narrow stare from an officer in one state, but cross a border and your ears might be permanently impaired by a wailing siren. The OBC has a listing of the states' trailer laws.

Are your tires inflated to the level the manufacturer recommends? Are your trailer lights and reflectors working properly? Does your insurance cover your boat and motor while being trailered?

On the road drive slower than normal. Do not learn the hard way that it takes longer to stop the car. This is because of the extra momentum unleashed by the loaded trailer.

Swing wide when passing other vehicles and making turns. When passing make sure the road ahead is clear of oncoming vehicles. Guard against pedestrians inadvertently walking into the side of the trailer. Give hand signals to warn other drivers. Use the outside rear view mirror. View from the inside mirror might be blocked by the boat behind.

Check the hitch and tie-downs each time you stop for gas. If you plan to park car and rig for a considerable length of time, loosen tie-downs to reduce strain.

For launching, you probably will use one of the many hard-topped ramps that are being built by communities, outboard boating clubs, marinas, yacht clubs, etc. Occasionally, you may launch from a natural site. In this case, choose an area with a sloping shore, but hard enough to give your tires ample traction. Sometimes you can gain better traction by deflating the tires slightly. But remember this when you start homeward. Stop at the first service station for air.

Perhaps you have experienced the prospect of a day's relaxation afloat vaporizing in those final few yards to the water, when car and trailer have been neatly maneuvered into a "V" shape. And it is no "V for victory." The only way to overcome this is by previous practice. Also have someone behind call instructions so you can back the trailer onto the launching ramp at a 90-degree angle to the water.

Remember that in backing, if you want the trailer to go to the right, turn the steering wheel to the left. If you want the trailer to go to the left, turn the steering wheel to the right.

Do not back the trailer into the water immediately. When in position on the launching ramp (or beach, if that is the case) stop the trailer a few feet from the water's edge. Release any tie-downs. But make sure the motor is tilted—you do not want it ramming into any obstacles. Then back the trailer, making sure the water does not reach the hubcaps.

Unlock the bow winch and secure a line to the bow. Push the boat down the trailer into the water, always holding the bow line so the boat does not float away. Unlock the trailer winch cable and with the bow line ease the boat into position for boarding.

Getting Aboard And Loading

If you are boarding from the beach, climb in over the bow. When boarding from a float or low pier, step aboard as nearly amidships (center of the boat) as possible. Bend so your weight is kept low. Grasp the gunwales (the boat's side rails) for balance. However, never step onto a gunwale unless you want to do something akin to a trapeze act. Even when lowering yourself from a high pier, try to step aboard amidships. However, if the boat has a forward deck, you first cara step aboard that.

Do not carry supplies at the same time you are boarding. You need all your equilibrium for the latter operation. If alone, place the supplies near enough so you can take hold of them from aboard the boat. Otherwise, have someone hand them to you.

A half pint of gasoline has the destructive power of five sticks of dynamite. In dealing with the boat's fuel, you are dealing with several gallons of gasoline. You can realize what could happen if this exploded. So take every precaution—leave nothing for granted.

It is wise, for instance, to remove the fuel tanks from the boat and take them ashore to fill. Extinguish all flames—including your cigarette's slow burn. Make sure the nozzle of the gas pump hose is in contact with the rim of the tank opening to prevent a spark of static electricity. Pour in a little gasoline. Add the required amount of fuel oil. Complete filling the tank with gasoline. Afterwards, make sure the lid of the tank is on tight to prevent leakage.

Aboard the boat check the fuel line for leakage. Correct the causes of leakage. If there has been leakage, or if you spill gasoline, carefully wipe the area with a rag. And thoroughly ventilate the boat before starting the motor.

It is essential—especially aboard a boat in which any areas are enclosed—that you be alert for gasoline vapors. These vapors are heavier than air. They crawl into the lower portions of the boat and wait, undetectable and menacing. So before starting the motor—or even lighting a match—be sure there are no gasoline fumes present.

Set the motor squarely on the center of the transom. Tighten the clamp screws as hard as you can. Check them periodically. They can work loose. With a screw loose, the motor can jump off the transom in rough water. Take precautions in case such a mishap occurs, unless you are a strong-armed and strong-willed skin-diver. Pass a line or a chain through a hole in the stern bracket. Make the line fast around something aboard the boat—preferably the transom knee or other brace-like structure reenforcing the transom.

Motor Angle, Trim And Efficiency

For best motor performance, the drive of the propeller should be in a line parallel to the keel of the boat and parallel to the flat surface of the water. This means you will set your motor at a 90-degree angle (or very close to it) to the water. In other words it will be straight up and down. If the propeller is tilted away from the stern, the bow of the boat tends to come up like the nose of a submarine while the stern squats. If the propeller is tilted towards the stern, the bow acts like that same submarine, plowing into the water as though starting to submerge.

The number of seats in a boat is not an indication of the number of persons the boat can carry safely. The extra seating is for the convenience of the passengers. But do not try to fill the house—or boat. You do not have to use each seat—or on the lake somewhere the boat is liable to fill with water. As has been said before, overloading is a frequent cause of boating accidents. Perhaps the best way to avoid overloading is by planning ahead of time how many people you can take and inviting just those. This saves you from the embarrassment of telling someone he cannot go. Which you probably would not do anyway, thus endangering the safety of all your passengers—and yourself.

Have the supplies and passengers evenly distributed (passengers seated toward the center-line of the boat and not hanging over the gunwales) so the boat will have proper trim and will perform as it was designed to do. If the load is concentrated forward or aft, the boat will function like a one-track seesaw. Someone may have to move forward or aft to redress the trim. But have this done before getting underway. It is dangerous to change places or move around in a boat (except for something bigger like an outboard cruiser—and then within reason) when it is out on the water. However, if for some reason this is absolutely essential, stop or slow the boat. (In rough weather, maintain some momentum so you can keep the boat under control and headed into the waves and wind.) Have the person bend low. He should grasp the gunwale with both hands. But he should also keep his center of gravity near the center-line.

You're Off!

If you have been in the army you probably have heard those endearing words from the drill sergeant, "Your other left, stupid!" But aboard your boat (not that you would have invited this worthy gentleman) he would have discovered that "other left"—that is if he tried turning the outboard motor like an automobile. (Do not confuse manual control with remote control. In the former you steer the motor by means of its handle. In the latter, you use a steering wheel, in most cases operating it like that in a car.)

A car follows its front wheels in turning. The boat gets its "orders" from the stern—from the "back-seat driver" so to speak. The motor not only provides the drive or power, but it also acts as the rudder for turning the boat. If you want your car to go to the left, you turn the steering wheel to the left. If you want your boat to go to the left (port) turn the steering wheel to the left. This moves the motor to the right, the propeller to the left. If you want your boat to go to the right (starboard) turn the steering wheel to the right. In reversing the opposite of these rules holds true.

Make a quick final check before getting underway. Do you have enough gas? Are your passengers seated properly? Is the way ahead (or astern, if reversing) clear of swimmers and obstacles?

Getting underway with a gear shift motor that has an electric starter is almost as easy as pressing a button—which is what you do to start it. Be sure the gear shift is in neutral. You do not have to cast off the lines until the motor is running smoothly. Then ease the shift forward or reverse and proceed slowly.
 
Do not stand during any of these operations—no matter how tempted when starting a motor without a gear shift. Here, you could easily use another set of hands. Because the motor starts on the run, you have to cast off first. But do not do so until just ready to pull the starter cord. When getting started and underway, sit facing in the direction your boat is going so you can see what is ahead.

Now a word of caution. If possible, shove the boat as far away from the pier as possible. And be sure the motor is not turned. Otherwise, when the motor starts the stern might swing into the pier. Unlike the automobile, the boat first responds to the steering response at the stern—not at the bow.

Now another word of advice. If possible, have the boat bow pointed at an oblique angle away from the pier. This will allow you to go ahead away from the pier before having to make a turning operation. Because the stern makes a wider arc than the bow in turning, the stern could whip into the pier at the same time that the bow is turning away from it. You have to watch this also when proceeding through congested areas, that in turning the stern does not swing into another boat, obstruction or swimmer.

Mooring And Docking

For purposes of the text, let us remain within the area of the pier. Let us assume that you have gone for a short practice run in the boat and now wish to return.

When making a landing, proceed slowly. You want the boat to make the approach slow enough so you can shift gears—provided your motor is of the gear shift type.

When landing on shore, watch for rocks, roots, obstacles. Avoid shallow water as much as possible. Usually, you can still operate the boat in shallow waters by taking hold of the motor at the rear, tilting it forward, and holding it in that position with one hand. The propeller will then be almost out of the water, still providing some momentum and at the same time being fairly safe from hitting underwater objects.

In landing at natural areas, try to select a sandy beach. Bring the boat in at a right angle to the site. Pull the boat up as far as possible so it will not be battered by waves.

But do not bring the boat into a pier or mooring at a right angle. The contact should be made at an angle almost parallel to the pier. Do not land on the weather side of the pier unless necessary. In this circumstance, you have less control over the boat because of the wind or current driving it toward the pier. However, you can check some of this momentum by putting the motor into reverse. If your motor does not have a gear shift, turn the motor around so that it is facing aft. This will check your headway.

APPROACHING AND LEAVING A FLOAT WITH AN OUTBOARD

The outboard boat has true "power steering" in that the direction of thrust of the motor, and not a rudder, guides that boat. As a result, outboard craft are exceptionally maneuver-able. They handle easily in reverse as the boat follows the motor, easing the process of approaching or leaving a float. With twin engines one can be driven ahead and the other astern to provide a very efficient means of turning in restricted waters. Technique of handling a single-screw outboard when approaching and leaving float is illustrated on this and the following two pages. (Approaching—Figures 1 to 4. Leaving—Figures 5 to 8.)

1. The float should be approached at an angle, with a crew member ready to get a bow line ashore. Fenders should be out.

2. When the crewman takes his line ashore, he makes it fast to a cleat on the float.

3. The pilot slips motor into reverse, turning his wheel to bring the stern toward the float.

4. The forward line will hold the boat fast as the motor brings it dockside. A stern line is then made fast to another cleat.
 
5. In leaving a float, when it is impossible to steer dead ahead, the stern line is taken in while the bow line is still fast to the float. The motor is reversed and turned away from the float.

 

6. A crewman releases the bow line and steps aboard taking in the line at the same time.
 
7. As the bow line is cast off, the pilot brings his wheel about to straighten his boat, continuing in reverse until well clear.

8. With both lines in, the pilot switches to forward and pulls ahead making certain his stern is safe in case he swings to port.
 
But try landing on the lee side of the pier. From this side you can head the boat into any wind or current. Thus, you will retain control of the boat. But from whichever side, just before the boat reaches the pier, turn the craft so that it comes alongside almost parallel. If you have a gear shift motor, use the reverse to stop the forward motion of the boat. Then shift back to neutral and make the landing with the motor still running. If your motor does not have a gearshift, throttle down to low speed, check headway by pivoting the motor 180° (which gives you reversing power), and get a bow line to the pier. Using the bow line as a spring to the pier, the stern can be brought in, if necessary, by going ahead slowly with the motor while the propeller is turned away from the pier. After the boat has come alongside, a stern line can be secured to the pier. (It is also wise to have fenders over the side of the boat to protect it from rubbing against the pier.)

Tying Up

You should have spliced an eye into one end of each dock line. Then they already have loops at the ends, making them easy to quickly throw over a bollard. Otherwise a couple of fast and handy knots are the clove hitch and bowline. You can learn about these and other knots in Chapter II on Knots, Bends, Hitches, Splices, in the first portion of this book. Further discussion on making fast is found beginning on page 146.

You should use at least a stern line and a bow line in making fast. For a short while, just a bow line will suffice for a small boat if it is docked on the lee side of the pier.

In tidal waters, be sure to allow for the rise and fall. Otherwise you are apt to return only to find your boat swamped or dangling unceremoniously out of the water—provided the cleats have not been torn from the deck.

Some sort of pulley arrangement will allow the lines and thus the boat to ride the tide. Barring that, you can run the bow and stern lines several bollards away from the boat—so that the lines are at angles of approximately 45 degrees to the center line of the boat. Done correctly, this arrangement will allow considerable flexibility.

Anchoring

Carry an anchor aboard even if you do not plan to use it. In boating you have to be prepared to do things for which you have not planned. In rough waters, anchoring will generally swing your bow into the wind or waves. You can also use the anchor to help get your boat free should it run aground. Carry the anchor 10 to 15 feet (or throw it if you have to) ahead or astern of the boat. Then pull on the line. When first let go, the anchor can also be used to check water depth.

The type of anchor you carry depends on the size of the boat, type of bottom you anchor in, etc. (More information on this can be obtained from Chapter VII, Anchors and Anchoring). Have the anchor line neatly coiled for running. Do not stand on it when lowering the anchor. Make sure the line is secured to the anchor. Aside from any hitch used when cleating the line on deck, the bitter (extreme) end should be made fast as well.

Do not attempt new records for throwing the "shot put." You do not throw the anchor overboard. You lower it over the side. But do not lower it while the boat is making headway. Wait until the bow is positioned over the spot where the anchor will lie. Then, just before the boat begins to gain sternway (drift backwards) lower the anchor easily until the crown hits bottom.

With the anchor on the bottom and the boat reversing slowly let out the line. As a general rule pay out a scope of approximately six or seven times the depth of water. This gives better holding power than a short scope of two or three times the depth. With too short a scope, the anchor may break out and let the boat go adrift.

An Exception To The Rules

The Rules of the Road under which you will be operating are thoroughly discussed in Chapter IV. But one exception must be stressed as it regards the small outboard boat. Even if your little craft has the right of way over some larger freighter or the like—it is the valor of discretion and of safety to turn aside for the big fellow. The outboard is likely to encounter such ships on some of the many rivers.

In fact, little boats should stay as far as possible away from the large commercial craft—particularly their wash. The propellers of large ships create a tremendous wake that could swamp your boat.

Remember, too, that large ships and towboats have certain "blind spots"—areas from which vision of the water is obscured or blocked entirely. Never assume the pilot of such a vessel can see your boat. And it takes several hundred yards to a couple of miles to halt such a vessel.

When meeting a tow in the bend of the river, or when a tow is maneuvering near shore, carefully note whether the tow is swinging to port or starboard. And stay clear.

You should not land or launch your boat near a moored barge. But if it is necessary, be cautious. Towboat operators say that strong river currents moving under the bow or stern of a moored barge can tend to pull a pleasure boat under.

Never tie up alongside a moored towboat or in a lock without the pilot's permission. He may not know your boat is alongside. Should he start the towboat, it could be disastrous for your boat.

Causes Of Accidents

OBC studies show the following to be the major causes of boating accidents:

1.Overloading and overpowering.

2.High speed turns. They may appear to be fun. But this kind of "horse play" can be dangerous.

3.Failure to keep a sharp lookout for other boats, rocks, reefs, snags and underwater obstructions.

4.Going out in bad weather. Those small craft warning flags are not hoisted for a parade. Find out if they are flying.

Check the latest weather forecasts—even when there is not a cloud in the sky—to see if a storm is on the way.

5.Standing up aboard a boat. If you have a properly matched, well-equipped outboard boat and you operate it in accordance with the rules of the road, together with common sense and courtesy for other boatmen, you will have gone a long way toward eliminating the possibility for accidents. But some possibility always remains. You should be prepared—"trained" is a better word—to act in an emergency.

Remember, the leading cause of deaths in boating accidents is drowning. Many of these fatalities result from people falling overboard. As the operator of your boat, you have a responsibility to know how to rescue someone. You should practice the maneuvers for accomplishing this. A ring buoy can be used to represent the victim. Many outboard boating clubs conduct "man overboard contests" to encourage the practice and mastery of this rescue operation. You should be practiced enough so you will be able to act practically from habit if the need arises. The minutes thus saved can be a life saved.

The OBC suggests a procedure somewhat as follows:

Immediately throw the stern away from the person overboard. (Remember the previous discussion in this text about turning the boat and motor and the wide arc the stern makes.) Having gotten the stern away from the person, shift into neutral if you have a gearshift. Otherwise you may have to cut the motor in the event you do not locate the person immediately. Throw a ring buoy or cushion alongside the person. (Let us hope you have made sure before embarking that each passenger knows how to use the lifesaving devices you carry.) See that you are clear before engaging the propeller.

Circle around quickly. Then approach the person, heading the boat into the wind or waves. You can also proceed into the wind or waves beyond the person, then drift back to him. But make sure you do not drift into him, and be sure the motor is stopped before making any attempt to take him aboard.

When alongside, extend a paddle or toss him a length of line. Lead him around to the stern only if there is sufficient space at the transom on one side of the motor to avoid any possibility of injury from the motor.

On many outboards the stern is so cluttered with the motor, gear and controls, that it would be necessary to help him aboard over the side, as far aft as possible, where stability is best. Other passengers should try to help trim the boat by shifting their weight to the opposite side to avoid capsize.

On very small boats without remote controls, it may be possible to remove the motor and take your man-overboard in over the transom. When helping a person aboard, you can grab him under the armpits and lift.

If the person has sunk from sight, probe gently under the surface with a paddle. Dive for him only if you are an experienced swimmer —and then only as a last resort.

What To Do In Emergencies

Stay with the boat if it capsizes. Do not try to swim for shore. It is farther than it appears. Most outboard boats have been made to float, even if filled with water. Fiberglass and aluminum boats usually have built-in flotation tanks. Some have been fitted with material such as Styrofoam to give buoyancy. Of course, your life preserver will give you that much added safety.

If your boat gets caught in a squall or in heavy seas, slow down immediately. Have all passengers put on life preservers. (Be sure to put yours on.) Generally keep the boat moving slowly, the bow headed at a slight angle into the wind and waves. Trying to smash through the waves at high speed could invite disaster. It is better to take the waves over the bow. The hull may pound, and the waves may throw up a lot of spray but you have better control over the boat.
 
If the boat gets caught broadside in a trough, you run the risk of a capsize.

If you find it difficult to keep the boat headed into the waves—or if the motor refuses to run, some kind of drag, like a heavy anchor, from the bow may help to keep the boat from falling into the trough. Very few boats carry sea anchors and opinions as to their effectiveness vary but as a rule one would expect to use such a rig only in a storm at sea under conditions where there was plenty of sea room—not the conditions an outboard is likely to encounter. If the motor is running and is of the gear shift type so the motor can be idled, it is best to keep the motor going so it can be utilized as quickly as possible to keep the boat under control.

Of course, you want to get to a protected anchorage if possible. Be careful of the course you take. Try to avoid taking large waves on the stern. They could swamp the craft. There's risk, too, with a heavy following sea, of being driven too fast before it. If you must turn in a heavy sea, watch for a lull so as not to be caught broadside in a trough by an approaching wave.

If your boat should exhaust its fuel supply, or if you need some other assistance, wave a white flag (white shirt or towel will do). Sound repeated blasts on the horn or whistle. Or fly the ensign upside down. At night, in addition to sounding the horn or whistle, use a red flare. Red flares, packaged especially for small boats, are now available in waterproof bags.

Where To Learn More

This text gives you some of the important points to remember in outboard seamanship. In addition, you may want to check manuals concerning the motor so you will know more about how it works, what you can do and not do in repairing it. But as for the seamanship —you can never learn enough. There are opportunities to learn more.

The United States Power Squadrons offer free courses in elementary piloting, seamanship, navigation, sailing, motor mechanics, weather, etc. For information on Squadrons in your area write the U. S. Power Squadrons national headquarters at P. O. Box 510, Englewood, New Jersey.

The U. S. Coast Guard Auxiliary also offers courses on piloting and small boat handling. For information on Auxiliary courses in your area, write to the Coast Guard Headquarters nearest you : New York, N. Y.; Boston, Mass.; Norfolk, Va.; Miami, Fla.; Cleveland, Ohio; St. Louis, Mo.; New Orleans, La.; Long Beach, Calif.; San Francisco, Calif.; Seattle, Wash.; Honolulu, T.H.

Outboard boating clubs and other local groups also offer courses.
 
How Much Power?

Safety depends in part on not overpowering your outboard boat. Here's a simple way to determine safe maximum horsepower.

The phenomenal expansion of the outboard industry within the short span of post-war years has brought into sharp focus two critical issues—the need for a broader safety consciousness among manufacturers and boat owners alike, and the desirability of some kind of code for the guidance of manufacturers.

Cognizant of the responsibility of manufacturers to unite and formulate a code tending toward maximum safety, the Outboard Boating Club of America has put years of study into the basic problems. As far back as 1948, they adopted a Maximum Boat Horsepower Formula designed to prevent the overpowering of outboard hulls. This was followed a year later with a Maximum Weight Capacity Formula to prevent overloading of the boat. With intelligent handling, power restricted within conservative limits, and a reliable guide in the hands of boatmen as to maximum loads their boats safely can carry, the groundwork has been laid for new standards of safety afloat.

In the early days of outboarding when low-powered motors were used to drive rowboats and small utility craft at moderate speeds, there was little need for standards to determine the amount of power that could reasonably be hung on the transom. Nowadays big cruiser hulls call for comparatively heavy, high-powered motors and, because of hull size, can carry them. But, in the scramble for speed, it is not at all uncommon now to find a big 70 hp motor or perhaps a pair of 50's on the transom of some small hull never designed to take them. Picture, if you will, two or three persons perched atop the transom of a small hull and you get a rough idea of what kind of load it is being expected to carry. This loading, of course, is also independent of any considerations of torque and vibration, which the bigger hulls are built to absorb.

High, then, on the list of recommended standards drafted by OBC is the one that enables the manufacturer (or the boatman himself) to calculate maximum safe horsepower for any given hull on the basis of a formula, with reference to one simple chart.

The Maximum Boat Horsepower Formula was originally adopted by the Outboard Boat Manufacturers Association (an affiliate of OBC) in 1948. To put it to practical test, OBC's Boat Capacity Committee ran a series of tests on hulls of various shapes and sizes in 1957 at Warsaw, Indiana. The outcome was a modification of the original horsepower curve, with reductions in the maximum horsepower ratings allowed small rowboats and larger outboards. The modified curve, which can be used to find the top allowable power for either one or two motors on a hull, is shown below.

Members of the OB MA use official OBC Capacity Plates on hulls of their manufacture to rate both horsepower and weight capacity. Though use of such plates is restricted to OBMA members, all boat-builders, regardless of affiliation with the association, are encouraged to use the formula to determine recommended maximum horsepower for their hulls. It will also serve as a valuable guide to owners of boats for which no rating was ever established.

How To Use The Horsepower Curve

Referring to the graph below, the first step is to multiply the overall length of hull by the maximum width at the stern. (Length in this case is to be measured from the face of the stem to the outer face of the transom at its highest point on a straight line parallel to the keel, excluding any extensions such as outboard brackets, fins, or similar accessories.)

OBC BOAT HORSEPOWER CURVE

Using the product of length-times-width (to the nearest whole number), find this figure along the bottom horizontal edge of the graph. Entering here, follow up to where your vertical line intersects the curve. Now follow horizontally to the left to find the maximum boat horsepower indicated along the left edge. If the intersection falls between figures, the figure directly above the point of intersection can be taken as the maximum horsepower for this particular hull.

To take an example, let's say we have a 15-foot hull (measured as specified) with a maximum width at the transom of 5 feet. The length-times-width-of-stern formula gives us a product of 75. Entering the graph at 75 on the horizontal axis (along the bottom) we follow the vertical line to its intersection with the curve and then follow horizontally to the left to the point of intersection with the vertical axis (at the left edge). Here we read the horsepower figure (interpolating between 55 and 60) as 57.5. Rounding it out to the figure immediately above the point of intersection, we get 60, which is the maximum power we can safely use on our particular 15-footer. We might elect to use a single motor of 60 hp, or perhaps two developing 25 or 30 hp each. In either case, we could select a motor (or motors) with confidence, on the assurance that not only theoretical calculations, but practical tests on typical hulls, show the power plant to be well within the limits of safety.

Stern-Width Significance

To emphasize the significance of the stern-width factor, let's say we have an older type of hull, also 15 feet in length, with a maximum transom width of only 4 feet (a hull, as the builder knows, designed for relatively less power and lower speed). To neglect the width factor and assume that this 15-footer could carry the same 60 horse, would be folly. In the first place, the large motor would be a waste of money to purchase. Also, it would cost more to operate. The power would probably be wasted because the hull might be badly out of trim with the excessive weight aft, and might not in fact be able to make any better speed than it would with half the power. But, most significant of all, the installation would be essentially unsafe, which outweighs in importance all other factors combined.

What power, then, to use ? Let's go back to the graph. Product of length-times-stern-width—now 60. Maximum power—30. End result—a more economical motor, to buy and to run—of lighter weight, thus easier to handle—of adequate power to drive the boat, probably, at maximum hull speed . . . and, above all, SAFE.
 
What's A Safe Load?

Never overload your boat. With formulas prepared by the Outboard Boating Club of America you can determine safe limits.

In Terms of safety in the operation of outboard boats, no factor rates higher than that of loading—the amount of weight a given hull is expected to carry, and the related matter of where that load is carried. Has any boatman spent many days afloat without seeing at least one instance of a whole family packed into a small outboard—several adults, children, even babies, the family dog, and a cargo of gear for the day's outing—occupants balanced precariously on gunwales half in, half out of the boat, others with feet trailing overside loaded on the forward deck, hull trimmed by the head till the bow eye is submerged?

The water's smooth, the sky cloudless, and our "yachtsmen" are having a hilarious time, cutting across the wakes and courses of every passing craft. Hasn't the owner bought a "seaworthy" boat? What does it matter how deep she's loaded, or how she trims? Unfortunately, the first time it comes on to blow a little, or a faster boat leaves him wallowing in a wash, he learns . . . the hard way.

Loss of the charter fisherman Pelican some years ago off Montauk Point threw sudden emphasis on a fact that all naval architects and sensible boatmen know almost instinctively—that every boat has a safe load limit, especially in heavy weather. The question is, in a practical way, how to determine it.

For outboarders, the Outboard Boating Club of America has provided an answer. In preceding pages, we have discussed OBC's standards manual for boatbuilders and manufacturers of outboard motors, trailers and equipment, with particular reference to their Maximum Boat Horsepower Formula. This provides the first sound basis on which to match power to hull, to avoid overpowering.

Following this up, OBC puts into the builder's hands another tool to promote safety—a formula permitting him to calculate the Maximum Weight Capacity of any outboard boat. Developed in 1949 for the Outboard Boat Manufacturers Association, whose members attach horsepower and weight capacity plates to the hulls they build, the formula was put to test in 1954 on Lake Winnebago (Oshkosh, Wis.) in a group of boats ranging from 12 to 16 feet in length.

What the formula provides is a figure for the total maximum weight of passengers, motor and miscellaneous equipment which any given hull can carry with safety. It is predicated on the theory that the load should never exceed 12.5 pounds per cubit foot of internal volume, with 12 cubic feet allowed per passenger of 150 pounds average weight. OBC encourages universal use of the formula among outboard boatbuilders, whether affiliated with OBMA or not; and every owner of an unrated boat would be well advised to calculate the weight capacity of his own hull. Here's how it works.

The diagram on page 297, reproduced from the OBC manual, shows a hypothetical hull in profile, plan and section at four transverse stations: A, ¾ length forward; B, amidships; C, Y\ length aft; and D, at the transom. Sections A, B and C divide the length (L) into four equal parts. Horizontal breadths (a, b, c, d, and e) are measured at top and bottom of height (H) and three intermediate points which divide height (H) into four equal parts. Measurements, taken inside the planking or plating, are expressed in feet, with inches and eighths converted to decimals of a foot carried out to three places. (See Table A.)

TABLE A

Conversion of Inches to Decimals in Feet
Inches              Decimals                      Inches              Decimals
(or fractions)     in Feet                          (or fractions)     in Feet
1/8"                  .010'                            3"                     .250"
¼"                    .021'                            4"                     .333'
3/8"                  .031'                            511                  .417'
'/2"                   .042'                            6·"                    .500'
5/8"                  .052'                            7"                     .583'
3/4                   .062'                            8"                     .667'
7/8                   .0 73                            9"                     .750'
1"                     .083'                            10"                   .833'
2"                     .167"                            11"                   .9171

Measurements made on the hull in accordance with the diagram provide the data needed to work out the Weight Capacity Formula. There are three steps: (1) compute areas of sections, (2) compute cubic capacity, (3) compute maximum weight capacity.

Step 1—Areas Of Sections

Areas of sections A (1/4 length forward), B (amidships), and C (1/4 length aft) are each computed separately according to the formula

On the theory that excessive freeboard in proportion to beam does not necessarily contribute to a hull's safety, certain maximum values (Table B) have been established for height (H).

Step 2—Cubic Capacity

The formula to compute the cubic capacity of the hull is based on the areas (determined in Step 1) for Section A, Section B and Section C. Substitute these for quantities A, B and C in the formula

Cubic Capacity of Hull = L/12 (4A + 2B + 4C)

Length (L) is taken from your measurements according to the diagram of Boat Interior Dimensions. Areas A, B and C are in square feet; the cubic capacity in cubic feet, to three places.

TABLE B

Maximum Allowable Height for a Transverse Section
Beam of Section           Max. Height     Beam               of Section         Max.
                                                                                                            Height

Up to 4.042'                 1.583'              5.710'              to 6.042'          2.083'
4.043' to 4.375'            1.667'              6.043'              to 6.375'          2.167'
4.376' to 4.709'            1.750'              6.376'              to 6.709'          2.250'
4.710' to 5.042'            l.8331             6.710'              to 7.042'          2.333'
5.043' to 5.375'            1.917'              7.043'              to 7.3751         2.417
5.376' to 5.709'            2.000'              7.376'              to 7.709"          2.500'

NOTE:—The maximum allowable height (H) is based on width (a) for that section on the Interior Dimensions. If the actual height of the section is less than the maximum allowable height, use the actual height. If the actual height of the section is more than the maximum allowable height, use the maximum allowable height.

Step 3—Maximum Weight Capacity

Calculation of the maximum weight capacity requires the multiplication of the cubic capacity (found in the previous step) by the factor 12.5 according to the formula

Maximum Weight Capacity =

Cubic Capacity X 12.5 lbs. per cu. ft.

The result is an overall total in pounds, expressing (to the nearest integer) the safe Maximum Weight Capacity of passengers, motor(s) and miscellaneous gear and equipment.

What we finally come up with, then, is a safe total load capacity —safe, provided the owner will use just an ordinary measure of horse sense. No law nor set of published standards will ever prevent him from going off shore with seas breaking on the inlet bar . . . nor from concentrating all his "safe" load forward under a spray hood on the run home before a following sea so his passengers can have shelter from a bit of spray.

Every boat, safely powered and safely loaded, has its limits—and that's where seamanship and competent boat handling enter into the picture.

The Flotation Formula

Assume, now, that the builder has taken pains to calculate the safe maximum limits of power and weight-carrying capacity for his hull, and has attached a plate specifying what these limits are. The buyer, then, abides by these restrictions but, in utter disregard of all precepts of sensible seamanship, he decides that "anything the commercial fisherman can do in his 30-foot inboard sea skiff, I can do better . ... in my 15-foot outboard!"

Is there nothing further the builder can do to protect the few that fall in this category from such folly, short of sending a Coast Guard picket boat to shepherd each one every time he leaves the anchorage? As a matter of fact, there is.

If a hull is expected to do the impossible, is driven beyond its limit and capsized, it may or may not sink, depending principally on the materials used in its construction, and the weight of attached motor and other gear. But regardless of what these weights are, flotation can be built into a hull by providing air chambers or enough buoyant material to support the weight, even when the hull is entirely submerged.

OBC's Boat Flotation Formula provides the means of calculating how much flotation material is needed for any hull, provided the total weight is kept within the maximum weight capacity determined by the OBC Maximum Weight Capacity Formula, discussed above.

The basic formula for flotation is F = W/B in which F = required amount of flotation material (expressed in cu. ft.)

W = pounds of flotation required

B = buoyancy of flotation material used (expressed in lbs. per cu. ft.)

Pounds Of Flotation Required (W)

W, the pounds of flotation required, is found from the formula

W = Ws + G + .10C in which Ws = weight of boat (submerged)

G = weight of motor, equipment and other gear (submerged) .IOC = weight of live load (submerged)

To find *WS {weight of boat submerged) use the formula:

Ws = WhKx + WdK2 + .69We in which Wh = dry weight of hull

Wd = dry weight of deck and superstructure

(If Wh and Wd are of the same material, they need not be measured separately.)

We = dry weight of factory-installed equipment, hardware and accessories

Ki = conversion factor for hull material (Table C)

K2 = conversion factor for deck and superstructure material (Table C)

(Note: Kx and K2 may be negative quantities when the material floats, resulting in minus quantities for Ws or its components.)
 
TABLE C Factors For Converting

Materials from Dry to Submerged Weight

Steel                          .88                      Walnut                                      —.54
Aluminum                  .63                      Douglas fîr plywood                   —.54
Fiberglass                  .33                      Oak                                          —.33
Molded plywood       —.49                  Mahogany                                —.11
Cedar strip                —.72                  Plylap                                        —.67
Redwood                  —.82                  Lapstrake (plywood strakes)    —.43

NOTE:—To calculate conversion factors for other materials, divide specific gravity of the material into that specific gravity minus one (I). For materials that float, \\\e specific gravity is less than one (I), the conversion factor will be a minus quantity, and the submerged weight of parts made of such materials will also be a minus quantity.

*The formula for Ws may be amplified for greater accuracy by a boatbuilder using several different materials in the construction of a boat. Parts made of each material are weighed and the weight multiplied by the conversion factor for the material used. The formula will yield an approximate weight, accurate enough in nearly all cases for use¡ in determining the pounds of notation needed.
 
To find G (submerged weight of motor, equipment and other gear) refer to Table D.

TABLE D

Submerged Weight Of Motor, Equipment And Other Gear For Outboard Boats Of Various Maximum Horsepower Ratings

Boat HP     Dry Wt.         Dry Wt.      Dry Wt.         Total       Submerged
Rating         Motor           Battery       Misc. ©ear    Dry Wt.   Weight (G)
0-10           75                 —              50                 125         86
11-20         95                 40              50                 185         127
21-40 (1)   145               40              100               285         196
21-40 (2)   190               40              100               330         227
41-60 (1)   250               40              100               390         269
41-60 (2)   270               40              100               410         282
61-80 (1)   250               40              125               415         286
61-80 (2)   290               40              125               455         313
81-100 (1) 350               40              150               540         372
81-100 (2) 500               80              150               730         503
101-150 (1)                    400            40                 200         640         441
101-150 (2)                    500            80                 200         780         538

Note:—(I) One Motor. (2) Two motors.

The largest element in this is the weight of motor (or "motors" in a twin-screw installation). The boat horsepower rating used in Table D is the maximum safe horsepower as calculated in the OBC Maximum Boat Horsepower Formula explained in the previous article. With each horsepower rating, there is listed the dry weight of such a motor (or the total weight of two smaller motors of approximately equal total horsepower) ; the dry weight of one or two batteries; and the dry weight of miscellaneous gear as might be carried by a typical boat in each of the horsepower categories. Finally, the total dry weight is translated into a figure for total submerged weight, and substituted for "G" in finding the pounds of flotation required.

To find .IOC (submerged weight of live load), first find the maximum weight capacity of the boat, as determined in Step 3 of the weight capacity calculations. From this subtract the total dry weight figure for motor, battery and miscellaneous gear listed in Table D alongside the appropriate boat horsepower rating. The difference in weights is the figure to be substituted for "C" in the formula for determining pounds of flotation required. Ten percent (10%) of "C" (dry weight of the live load) is the .IOC representing the submerged weight of the live load.

From the foregoing calculations we have found Ws (submerged weight of boat), G (submerged weight of motor, equipment and gear), and .IOC (submerged weight of live load). The sum of these combine in the formula

W = Ws + G + .10C which gives the "W" (pounds of flotation required) for the formula

F=W/B

Buoyancy Of Flotation Material Used (B)

The next step is the determination of "B," the buoyancy of the flotation material used. If air chambers are to be built in, "B" will be 62.4 (the weight of one cubic foot of fresh water). If some other type of flotation material is to be used (Styrofoam, for example), "B" will equal 62.4 minus the weight of one cubic foot of the particular flotation material used, less appropriate allowances for its water absorption and adsorption characteristics. "B" is expressed in pounds per cubic foot.

Cubic Feet Of Flotation Material Required (F)

Back now to the original formula F = W/B we have seen how to determine the values for "W" and "B," so the final step is to solve for "F." This is done by dividing the pounds of flotation required (W) by the buoyancy of the flotation material used (B). The quotient is the amount of flotation material required (F), in terms of cubic feet.

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