Motorboating Start to Finish E-Book

Barry Pickthall

• Herausgeber: Fernhurst Books Limited
• Kategorie: Lebensstil
• Sprache: Englisch

Veröffentlichungsjahr: 2019

Beschreibung

Motorboating Start to Finish is the perfect book for you if you are new to motorboating and need to learn the basics, or if you are experienced, but wish to broaden your skills and develop your techniques. This easy-to-follow, step-by-step guide takes you through the basic principles, preparing to go to sea, your first voyage and safety at sea. It includes advice on choosing and buying a motorboat, essential equipment, boat handling, tides, weather and navigation, all taken from courses delivered by the UK's biggest sailing school, the UKSA. This book is accessible to all levels, giving those new to motorboating straightforward advice, and showing experienced powerboaters how to take the sport to the next level with professional tips that will help improve speed, skill, safety and enjoyment. It is a complete reference for every level of tender, RIB, fishing boat, motor cruiser or sportsboat driver. This book is packed with hundreds of illustrations and photographs, and is a great way to learn, develop and refresh your powerboating skills.

Leseprobe

Contents

Getting started

1Basic principles

Powerboat types

Parts of the boat

Propulsion systems

Buying a powerboat

Transporting and launching trailable powerboats

Knots and ropes

2Preparing for sea

What to wear

Essential equipment & safety checks

Getting onboard from dinghy and dock

Rules of the road

3First voyage

Boat handling and trim – mooring and anchoring

Tides and weather

Basics of navigation

Pilotage and passage planning

Radio etiquette

4Safety at sea

Passage planning

Navigating in restricted visibility

Boat handling in heavy weather

Registering your vessel and voyage

Towing

Fire prevention and control

Man overboard

5Glossary of terms

Acknowledgements

Getting started

I was first drawn to powerboating as a child through a passion for fishing. Rather than wait for the fish to come my way, I soon learnt that it was far more profitable to chase after them. I rigged up a small outboard on the back of the family dinghy and spent endless hours trawling for mackerel or sitting anchored off the beach with worm-baited lines pulling up Dover sole.

From there it was a short enthusiastic jump first to waterskiing, then fast cruising from port to port. It is an adventurous, exciting, and fun sport that can appeal to all the family.

A fast seaworthy power cruiser can carry you a long way in a day: across the English Channel to taste the delights of French cuisine, run across the Gulf Stream from Miami or Fort Lauderdale to spend the day on a deserted beach in the Bahamas, or simply to get out to where the fish are running.

The latest electronic navigation aids take the guess and stress out of navigation, and the ability to cruise at 20+ knots becomes a major safety factor, giving you the ability to outrun bad weather.

Nowadays, many people discover the delights of getting afloat later in life, bypass the small fishing dinghy inauguration altogether and are introduced through friends or experiences on holiday, straight to high powered sports fishing or power cruisers.

That’s fine, but buying a powerboat is often one of the biggest expenditures many of us will make, so it is prudent to know what you are doing before going afloat, or at least to have an experienced hand onboard to show you the ropes. Better still, enrol on an introductory powerboating course like those organised by the UKSA to learn not just the rudiments of getting a boat to go where you want it to, but how to dock, communicate and navigate safely. These are all essential skills, and your choice of boat will be all the more informed once you are competent – and confident – enough, to take her out for the day or weekend.

This powerboat manual takes you through a step-by-step guide based on the UKSA’s teaching programme and is designed to provide readers with a thorough grounding to enable you to manoeuvre, plan and make a passage safely.

Powerboating is a great recreation, not just for moving from A to B but opening opportunities to scuba diving, fishing, waterskiing and socialising. Whether your choice is an Orkney sports fishing boat, a Ribtec rigid bottom inflatable (RIB) or a power cruiser like the Tony Castro-designed Galleon 44 flybridge cruiser – all featured in this book – everyone has the opportunity to enjoy being afloat.

You will love it!

Barry Pickthall

Powerboat types

What type of powerboat should I buy? The first-time buyer is confronted with a bewildering choice of shapes and sizes, some of them very specialised and intended for varying conditions and uses. If your interest is fishing on rivers or lakes, then a small flat-bottomed boat that is light, stable and easy to transport could well be the boat for you.

Fishing offshore requires a more rugged design with greater freeboard and a hull shape that will slice through the seas rather than bounce uncomfortably over them.

Should cruising be your prime interest, then the size and number of berths may be your first consideration, but running costs and where to keep her should be a close second.

Hull shapes

Hull forms can be divided into two broad categories: displacement and planing.

Planing hulls obtain their dynamic lift from a combination of hull shape and the speed at which they move through the water. As speed increases, the hydrodynamic forces lift the hull up on top of the water, reducing drag and wave-making resistance to allow relatively high planing speeds. The transition point between displacement and planing is known as ‘hump speed’. This is where the hull generates enough ‘lift’ to rise up on top of the water and accelerates forward just as if a turbo has kicked in when driving a car.

Planing hull in slow displacement mode.

Same hull in full planing mode.

Displacement hulls

Traditional, non-planing types are known as displacement hulls. Working on the Archimedes’ principle that a floating object displaces its own weight of water at rest as well as at speed, these traditional hull shapes are continuing to push aside their own weight of water, setting up a wave at the bow and stern.

As speed increases, the height and distance between these two waves increases to the point where the hull is supported in the water by the wave generated by the bows, and the other at the stern, with a big dip in between.

At this point, the boat has reached its maximum displacement speed. This figure is in direct proportion to the length of the hull and can be calculated quite accurately using the equation:

Wave pattern of a displacement hull operating at its design speed.

Wave pattern of a displacement hull operating above its design speed.

Thus, a displacement hull with a waterline length of 25ft (7.62m) has an effective top speed of just under 7 knots.

If more power is applied, the hull will try to climb up its own bow wave, and the stern wave will fall back, leaving the transom to sink down in the trough, creating a great deal of wash and a wasteful consumption of fuel. Any further increase in speed can only be achieved by an inordinate and highly inefficient use of extra power.

Semi-displacement hulls

A semi-displacement hull is a hybrid of these two types, combining V-shaped forward sections that merge into a flat or rounded profile aft. When pushed above displacement hull speed, this design type operates at the lower end of planing mode speeds, providing a comfortable – though wet – ride through heavy seas. It is not as fuel efficient or as fast as a fully planing hull and invariably rolls more.

Nelson semi-displacement hull. Excellent sea boats, but very wet.

Elan 35 deep-V sports cruiser running at speed.

A deep-V hull in displacement mode.

A deep-V hull in planing mode.

Planing hulls

The deep-V hull is the most popular form for fast offshore fishing and cruising powerboats. The sharp entry of the bow and V-shaped bottom, carried all the way back to the transom, minimises slamming and smoothes the boat’s ride over waves. The widely flared bow adds to the forward buoyancy, limiting any tendency for the hull to bury its nose when running through following seas, and the addition of spray rails to knock down spray, also contribute to this ‘lift’. At slow speed, the deep-V hull has more draught than a flat planing hull and behaves much more like a displacement design. The deeper the V or angle of deadrise, (often between 18° and 25°) the better the performance and ride in rough water. The trade-off is less speed in calmer conditions than flatter bottomed designs.

Some designs incorporate a ‘step’ in the hull approximately 2/3rds of the way back from the bows. Also known as the ‘vented’ hull, the step is designed to suck air under the aft sections of the hull to lessen the wetted area and resistance. The bubbles of air sucked into the flow act like ball bearings to reduce friction.

Cathedral hulls

Orkney cathedral hulled unsinkable dory.

The vented Intrepid sports fishing hull. Air is sucked down through the step to lessen wetted area and resistance.

The cathedral hull is a triple V-shaped planing monohull originally developed in America. It offers a wide rectangular full-length cockpit coupled with remarkable stability and load carrying capabilities. These open dories make excellent tenders and inshore rescue craft.

Catamarans

Powered catamarans are popular in Australia and parts of America, where they are used as fast fishing boats. These twin-hulled designs combine the good stability characteristics of the cathedral hull with the sea-keeping qualities of a deep-V hull. Their performance is, however, more susceptible to weight than a deep-V hull.

Glacier Bay power catamaran.

Orkney Vanguard traditional sports/fishing boat

Orkney Boats have been building traditional go-anywhere sports fishing boats for more than 3 decades. The 19ft Vanguard used in illustrations throughout this book marries the traditions and strength of moulded clinker planking with the get-you-homesafely all-weather performance of pilot boat design thinking.

Built in Britain, the Orkney range of sports fishing boats can be found all over the world. Produced in sizes from 13–24ft (4–7.3m) the larger boats within the Orkney range have fully fitted cabins, while the smaller fishing boats can be purchased as open boats or with the addition of a fixed and folding cuddy.

Orkney Vanguard 190

Length:

19.40ft

5.91m

Beam:

7.50ft

2.29m

Draught: (engine down):

2.50ft

0.76m

(engine tilted):

1.00ft

0.30m

Internal freeboard:

2.40ft

0.73m

Displacement:

2,359lb

1,070kg

Trailed weight:

3,240lb

1,470kg

Max engine:

100hp

Max speed:

30 knots

Max payload:

6 persons or 1,323lb

Transport:

trailer

Design stability category:

C

Ribtec rigid bottom inflatable – RIB

The concept of marrying a deep-V hull to an inflatable collar around the gunwale was first developed by Atlantic College in Wales back in 1967. The idea was then carried forward by the Royal National Lifeboat Institute (RNLI), which put a number of Atlantic 21 inshore lifeboats on station around the British Isles. The concept was then adopted by the military as rapid assault and rescue craft.

During the 1980s the good sea-keeping capabilities of the deep-V hull and inherent safety of the inflatable tubes which keep these boats buoyant even when full of water, has attracted a strong allegiance among the boating public worldwide. The Ribeye 6m RIB featured in this book is produced by Ribtec Ltd in the UK and is a fine example of the genre in terms of handling, performance, seakeeping qualities and safety.

Rebtec Ribeye 6 metre RIB

Length:

19.68ft

6.00m

Beam:

7.48ft

2.28m

Draught: (engine down):

2.50ft

0.76m

(engine tilted):

1.54ft

0.47m

Tube diameter

1.50ft

0.46m

Air chambers:

5

5

Displacement:

1,962lb

890kg

Trailed weight:

2,844lb

1,290kg

Max engine:

120hp

Max speed:

40 knots

Max payload:

8 persons or 2,425lb (1,100kg)

Transport:

trailer

Design stability category:

B

Galeon 440 Flybridge sports cruiser

The 44ft (13.42m) Galeon 440 Flybridge sports cruiser used in illustrations throughout this book is designed by Tony Castro and built in Poland. She is a particularly good example of the flybridge cruiser design with a large saloon, expansive ‘owners’ suite and two guest cabins. Stairs from the aft cabin lead up to the flybridge to provide a commanding position for the helmsman, and seating and sunbathing areas for guests. There is a second steering console at the forward end of the main saloon for when the weather is inclement. Powered by twin Volvo Penta diesel engines, she has a 400 mile range and cruising speed of 25 knots.

Length:

44.03ft

13.42m

Beam:

13.45ft

4.10m

Draught:

3.94ft

1.20m

Displacement:

20.08 tons

18,216kg

Max engine:

2 x 420/575KW/PS

Max speed:

33 knots

Crew limit:

12 persons

Design stability category:

B

Crew:

6 people

Edgewater 245 Centre console sports fishing boat

The 24ft 5in (7.4m) Edgewater 245 is typical of the deep-V centre console sports fishing boats developed in America to carry you across the Gulf Stream to the fishing grounds and dive wrecks in the Bahamas or Catalina Islands off California.

These boats are extremely versatile. Their deep-V hulls cut through waves with ease while their high freeboard and wide midsections give added stability and the confidence to run at speed through beam and following seas. The designs have builtin fish and bait boxes, rod holders and stowage space, and larger models like this Edgewater 245 even have an enclosed toilet built into the central console.

Length:

24.50ft

7.40m

Beam:

8.50ft

2. 60m

Draught: (engine down):

2.50ft

0.76m

(engine tilted):

1.74ft

0.53m

Internal freeboard:

2.30ft

0.70m

Displacement:

3,400lb

1,543kg

Trailed weight:

3,240lb

1,470kg

Max engine:

350hp (single or twin outboards)

Max speed:

45 knots

Max payload:

11 persons or 3,700lb

1,680kg

Transport:

trailer

Design stability category:

B

Parts of the boat

3D Rigid inflatable boat (RIB)

Inflatable dinghy

Galeon 440 Flybridge cruiser

Propulsion systems

There are four types of propulsion – the outboard engine, the inboard engine, the inboard/outdrive and the waterjet. All these propulsion systems rely on the screw propeller to provide the thrust.

The propeller has radiating blades that form part of a helical or spiral surface and operates like an auger cutting a hole through wood. A propeller’s thrust is proportional to the mass of water it is acting on. Large-bladed propellers with less pitch are more efficient than smaller props with a deeper pitch. On small pleasure boats, limited draught and constraints of clearance from the hull conspire to limit prop diameter to something smaller than optimal size. Their performance depends on the area and pitch of the blades. This is measured by the theoretical amount the propeller will move forward with each complete turn. Thus, a 25¼ -inch (33cm) pitch propeller will move that distance with each revolution.

In practice, propellers perform well below their theoretical pitch figure because no account is made for the weight of the hull and the resistance the boat generates in the water. The figures are distorted even more by the speed at which the propeller turns.

Pitch is the theoretical distance that the propeller will travel on one rotation.

In practice propellers perform well below their pitch figure because of cavitation and slippage.

The faster the spin, the greater the cavitation, or bubbles that form on the blade tips when the prop is under load. Cavitation is caused when the pressure on one part of the blade falls below ambient pressure (atmospheric + hydrostatic head), and a vacuum is formed. This is often experienced during fast acceleration and sharp cornering. The telltale signs are a sudden increase in revs and a reduction in speed.

Propellers have improved considerably over the years, and most engine manufacturers offer an advice service to match propeller type and pitch with the type and use of your boat. Three-bladed propellers provide a greater top speed at the expense of low-end acceleration. Four-bladed designs have better low-end power but at the expense of top-end speed. Volvo Penta’s Duoprop and IPS forward facing dual prop outdrive legs have two contrarotating props which increase efficiency by as much as 15% and eliminate prop walk.

Zinc sacrificial plate fitted close to shaft and bronze prop, rudder and P-bracket save them from electolytic action.

Lightweight electric outboard.

Standard propellers supplied with outboard and outdrives are invariably aluminium. These are easily damaged and, since any chinks on the trailing edge of the blades can have a marked effect on performance, these are often replaced with more durable stainless steel propellers.

Composite props provide a cheaper alternative and some designs have the provision to replace individual blades if they are damaged.

Bronze propellers are often used on inboard powered boats kept afloat because of their greater resistance to corrosion. Zinc sacrificial anodes must be fitted on the shaft and hull to overcome electrolysis problems associated with saltwater applications.

Outboards

The outboard motor is the most common form of propulsion for smaller boats, offering compact weatherproof units from 1.5hp to more than 300hp. At one end of the market are the light, simple, battery-powered electric auxiliaries used to power a tender or provide super-quiet manoeuvrability when fishing. At the other end are the compact 2–3 litre race-bred models with sophisticated electronic engine management systems. In between is an enormous choice of engines, including two and four-stroke, powering props or waterjet systems.

Two and four-stroke systems have very different characteristics. The two-stroke has a better power-to-weight ratio and superior low-down torque than a four-stroke, making them a better choice for waterskiing and other applications where fast acceleration is required. On the downside, they use more fuel than a four-stroke and produce greater emissions.

The four-stroke really scores with more torque at the top end of the rev range, coupled with quieter, smoother running without the smoky exhaust that remains a trademark of all two-strokes.