Über die Autorin bzw. den Autor

Niger Calder is the author of Marine Diesel Engines (1987, 1991) and Boatowner's Mechanical and Electrical Manual (1989, 1995), the success of which has made him the most sought-after marine how-to writer in the U.S. and U.K. He has published more than 800 magazine articles in SAIL, Cruising World, Ocean Navigator, Yachting World, etc., and lectures on cruising to sell-out crowds. He is also the author of The Cruising Guide to The Northwest Caribbean (IM, 1991) and Cuba: A Cruising Guide (Imray, 1996). He will be testing his newest ideas with his family during a six-month cruise to the Caribbean and South America this winter.

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Instant answers for your boat handling, navigation, and seamanship questions

The Instant Handbook uses a dynamic new quick-reference format to cover the critical aspects of piloting, seamanship, and boat handling under sail or power more accessibly and effectively than has ever been done before. It puts at your fingertips all the information you need about:

• Boat Handling Under Power--Bob Sweet
• Sail Trim and Rig Tuning--Bill Gladstone
• Using Nautical Charts--Bob Sweet
• Using GPS--Bob Sweet
• Using VHF and SSB Radios--Bob Sweet
• Rules of the Road and Running Light Patterns--Charlie Wing
• Knots, Splices, and Line Handling--Charlie Wing
• Anchoring--Peter Nielsen
• Onboard Weather Forecasting--Bob Sweet
• Heavy Weather Sailing--John Rousmaniere
• Diesel Engine Care and Repair--Nigel Calder
• Emergencies On Board--John Rousmaniere
• Emergency First Aid On Board--Richard Clinchy

Each subject is stripped to its absolute essence. Only a panel of top nautical experts could pack such a wealth of information into such a small book. Equally valuable for home study and onboard reference, The Instant Handbook includes all the essentials and not a word more.

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The Instant Handbook of Boat Handling, Navigation, and Seamanship

The McGraw-Hill Companies, Inc.

Contents

Chapter One

Know Your Boat

Every boat under power moves in reaction to the thrust of water discharged from its propeller. When the discharge stream is directed astern, the boat moves ahead, and vice versa.

(1) The operator of an out-board, sterndrive (inboard/out-board or I/O), or jet-drive boat steers by directing the discharge stream from side to side—and that makes these boats highly maneuverable as long as the engine is engaged.

(2) In boats powered by a conventional inboard gas or diesel engine, the propeller is mounted on a fixed shaft, so the boat must be steered solely by means of a rudder. Add a second engine, however, and the engines and steering working in concert make the boat highly maneuverable, as we'll see.

The following table is for comparative purposes. Any production boat will handle sufficiently well provided you adapt your handling techniques to your boat's tendencies rather than trying to fight them.

1. with engine in gear—does not respond to helm when engine is in neutral

2. with both engines engaged ahead or astern

Slow-Speed Maneuvering

A powerboat turns on a center of rotation that is typically about one-third of the way from the bow to the stern (1A).

In effect, your boat's propulsion system pushes the stern away from the turn so the bow will rotate into it, and the stern swing is wider than the bow swing. Also, due to its momentum, your boat slides into a turn rather than carving it like a car on a curve (2).

You need to be aware of these effects or you are likely to strike with your stern the very boat or dock you turned your bow away from (3). In time you will learn what clearances your boat requires for turns at various speeds and in various conditions of wind and current.

In reverse, a powerboat's pivot point typically moves to about two-thirds of the way from the bow to the stern, so the bow now swings more widely (1R).

The pivot point on a sailboat is more nearly amidships (1C).

Single-Engine Inboard

A single-engine (single-screw) inboard powerboat depends on its rudder for steering. When the engine is in forward gear, the rudder turns the boat by deflecting the prop discharge (often called "wash") as well as the current created by the boat's motion. At slow speeds the boat depends heavily on prop wash for steering control; the smaller the rudder, the more true this is.

The propeller also produces a small side thrust that pushes the stern to port or starboard. Most boats use a "right-handed" prop, which turns clockwise in forward gear when viewed from astern, pushing the stern to starboard. Take your cue from the direction the blades are moving at the top of the swing; that's the direction of this so-called prop walk. Prop walk will give your boat a tighter turn to port than to starboard in forward gear.

When you put the single engine in reverse, however, the direction of side thrust also reverses, and the impact is greater in reverse than in forward since the propeller is not as efficient in reverse. To compound the problem with a single-screw inboard, in reverse there is no prop wash on the rudder to help with steering. To counter the stern moving to port, briefly shift the engine from reverse to forward and apply a brief burst of power while you steer hard to port. Then shift back to reverse. You won't make any forward headway, but the stern will kick over to starboard.

You can use prop walk to help you make a slow closequarters turn to starboard. First turn the wheel hard to starboard and apply a brief burst of power (1). This should turn the boat 20 degrees or more. When you start to make forward progress, apply a brief burst of reverse power (2). The resultant side thrust "walks" the stern to port, continuing the turn while slowing your forward motion. Repeat the process (3) until your turn is completed. With practice, you'll be able to turn a clockwise circle within the boat's length.

Turning counterclockwise is more difficult because prop walk—while it aids the turn in forward—opposes it in reverse.

Twin-Engine Inboard

Twin inboard engines with a rudder behind each prop make a highly maneuverable boat. Usually the starboard propeller will be right-handed and the port prop will be left-handed, so that their side thrusts cancel when both engines are in forward (1) or reverse (2). A twin-engine boat will therefore back straight when you center the rudders (absent wind or current) and is steerable at low backing speeds.

When one engine is in forward while the other is reversed (3), the side thrusts combine to make a turn even tighter. When rudder action is added, the boat can even spin within its own length.

You can often maneuver with engines alone. E.g., backing with more throttle on the port engine turns the stern to starboard (4).

On some boats, you can even slide the boat sideways. Try putting the starboard engine in reverse and the port engine ahead with left rudder.

Outboard and Sterndrive (I/O)

Single-engine outboards and sterndrives steer by turning the propeller so as to direct its discharge current. These boats permit easier steering in reverse and tighter turns than you can possibly get from a single-engine inboard.

Without a rudder, however, there is little steerage with an outboard or I/O if the propeller is not engaged. This means it's more difficult to approach a dock with the engine in neutral. Also, most outboard-and sterndrive-powered hulls are designed for planing, not slow speeds. But you soon learn how to use throttle and helm to handle the boat.

Twin outboards or stern-drives offer some of the same handling benefits as twin inboard engines, but not to the same degree, since the propellers tend to be much closer together and farther aft from the boat's center of rotation than inboard props.

Planing hulls are designed to go fast, and track better going forward than in reverse.

Jet Drives

A jet drive has no external propeller. Instead an internal impeller mounted in a tube sucks water in through a grate in the hull bottom and forces it out toward the rear to produce thrust much like a jet aircraft. Steerage is accomplished by turning a nozzle to direct the discharge. When it's time to back up, a deflector shield swings down over the nozzle outlet, directing the discharge thrust forward. This produces a small and relatively ineffective reverse that can be steered for directional control.

Jet drives operate like outboards or sterndrives with nearly instantaneous response. However, the jet drive has no steerage without power applied.

Auxiliary Sailboats

A sailboat's larger rudder makes it slightly more steerable in reverse when the boat is moving than a single-engine inboard powerboat. The sailboat's keel or centerboard will help it track through turns and provides a pivot point fixed nearer amid-ships. That means the stern kicks out less in a turn ahead, and the bow kicks out less in a turn astern.

However, a typical lack of horsepower imposes restraints. Prop walk is likely to be significant, especially in reverse. Adapting the approaches for...