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'Trailer sailer' is a term used to describe a sailing boat that has been designed to be easily transported using a road trailer. It is neither a Day sailer or a Pocket cruiser but may be used for either purpose depending upon design suitability. The large dinghy style relies principally on correct crew weight for balance rather than fixed ballast, much like a dinghy and is suitable for use only on protected water. The other style is a Trailer yacht, which has a proper yacht ballast ratio of at least 30% excluding crew weight. This latter style is suited to yacht racing or cruising on inshore waters and along coastlines; a good example may pass self-righting tests and be suitable for Junior Offshore Group (JOG) or English Channel events or similar. Other designs are a compromise between the two principal types. An emerging type is the Sportsboat with a proper yacht ballast ratio, but large sail areas requiring crew weight positioning for stability, with their own design and self-righting rules. One feature that distinguishes Trailer Sailers from other small yachts is the need to launch from and recover to a road registered trailer, which can place constraints on dimensions and weights. They may vary in length from 5 to 10 metres; above that the length-width ratio is not ideal. In addition the mast and rigging must be suitable for ease of raising and lowering. The keel is most often not fixed but may be retracting, removable or swing, hydraulic, winch or electric operated and the ballast may be water that is drained to reduce weight for trailing. For simplicity and weight saving they are more likely to have a removable outboard engine.
Inherent in the design of yachts with lifting keels is the ability to approach a beach or landing close enough that the occupants may wade ashore. Such craft can sit on the bottom comfortably when the tide recedes (often referred to as "drying out"). Shallower cruising grounds can also be more readily, and safely, accessed. Lifting keels also permit the boat to be stored on the trailer at home or onshore at a marina or boat club rather than on a mooring, thus making them cheaper than larger boats. Another advantage is the quick movement between different cruising grounds: it may take weeks to sail a yacht to a new destination, whereas it may take only days to transport it by road .
In this area trailer sailers, and particularly trailer yachts, are different from day sailers and pocket cruisers in that they are more likely to be designed for, or under the influence of, a measurement rule for yacht racing on handicap and overnight. Measurement rules not only determine the shape of a yacht but also affect the sail plan, and will even specify the accommodation requirements, such as the number and type of berths, galley equipment and water storage and even whether a head (marine toilet) is required. Depending on whether a yacht is to be raced in harbour (protected water) or outside along coastlines, or offshore, different self-righting specifications will have to be met in the design. Each trailer sailer design, however, is a compromise between speed and cruising comfort and stability.
In monohull yachts, hull shape is very much affected by measurement rules. See Hull (watercraft) In some countries the maximum width, length or weight is restricted by road regulations. Waterline length is the determinant on displacement water speed, the speed in knots very roughly is proportional to the square root of the waterline length in feet. So a 16 ft boat can do 4 knots and a 25 ft boat about 5 knots, not a lot of difference, unless you sail in tidal waters and face a 3 knot current where the larger boat will advance at twice the speed. The larger boat may also have 3 times the volume, which helps cruising comfort. Larger boats have more headroom.It is rare to have full head room in a boat smaller than 25 ft. Some trailer sailers have pop tops, a lifting canopy that gives full head room in smaller craft. The shape below the gunwales will be determined more by handicap measurement rules and these vary between countries. Also they will vary depending on construction method. Plywood kits and plans for plywood will likely be of single or multi chines construction. Fibreglass production boats will be very smooth and rounded and can include complex curves. This advantage in hull shape though can be offset by the much higher weight of glass, unless composite materials are used. The racing advantage that trailer yachts have when racing in mixed fleets is the ability to exceed displacement speed downwind on waves known as surfing. Most yachts will surf given the right conditions, often extreme, but for a light weight trailer yacht it may surf in the harbour on one metre waves and outpace larger displacement yachts up to twice their size.Lighter trailer sailers especially sports boats will plane in moderate breezes. Measurement rules which design yachts for all round performance have difficulty with this factor. For a normal yacht the less drag a hull has the faster it will go, particularly in light breezes and upwind, and here is the compromise, this usually means the stern of a yacht will decrease in width from the midsections aft. But this is not the ideal shape for surfing or planning where a wide stern with flat run aft is best. Thus trailer sailer hull design intended for racing will compromise upwind performance and rating for surfing and rating beating ability. Larger yachts are now following this trend. Trailer sailers are usually designed to spend most of the time on a trailer. The keel construction must be strong as it bears most of the weight of the hull plus crew. Trailers must be strong with multi rollers to assist in launching and retrieval. Smaller boat trailers use a geared winch of 1:3 or 1:5 while above 20 ft most use an electric winch.
To be trailable there is a limited number of alternative keels that can be used. In general there is the drop keel or swing keel . For any keel that retracts into the yacht a centreboard case to house it is required inside the yacht. For drop keels full cabin height cases are usually required under safety rules. Swing keel cases can sometimes be kept beneath floors and intrude less into the cabin, but are considered less efficient than a drop keel . Although keels must be locked down when racing, the swing keel has safety advantages for if it runs aground the keel will kick up and either slide over an obstruction or slow the boat, whereas a drop keel will stop a yacht abruptly. A drop keel can be sailed with the board partly raised without upsetting the centre of hull resistance and balance of the boat. A swing keel is a liability for if the yacht capsizes without the centreboard fixed, when inverted the board can swing in and damage the case top, leaving a leak below waterline . To enable sailing with the board partly raised yachts will sometimes carry extra ballast beneath the floors fixed inside the hull, or use a large bulb at the bottom of the board that contains most of the weight. Self-righting tests are sometimes specified for such arrangements.
The rig is the mast and stays or rigging to keep it in place. Because of trailering the need is for it to be raised and lowered to the deck easily. On smaller sizes this can often be manhandled by one or two people but in larger boats mechanical assistance is required. On pure racing boats light tall whippy masts are used but these require running backstays to keep them up, which must be changed each time a boat tacks or jibes. These hinder short handed cruising. Flexible masts can be bent to unload air and maintain drive. Trailer yachts designed for cruising and casual racing are likely to have heavier section masts, without running backstays and these are more difficult to raise and lower. The mast must be steadied both longitudinally and sideways whilst raising and lowering. Ideally the side stay connections remain in place so that on raising a mast tuning is not altered each time. Trailer recovery winches can be utilised to raise the mast and spinnaker poles double as hoisting derricks.
Most trailer sailers cater for a variety of uses. The ideal sail-plan for this is the fractional rig with the ¾ fractional being popular. Fractional rigs are where the height of the foresail only comes up to a fraction of the height of the mainsail. With these rigs the mainsail is the powerhouse and trimmed first, the advantage for cruising is that the centre of effort of the main sail in relationship to the centre of resistance of the hull is such that the boat will usually sail under main sail alone . The headsail can be on a furler to reduce sail or furl away easily without the need to go onto the foredeck. Furler sails may not as efficient for racing, so a separate head sail may be needed for this purpose. An alternative is the self tacking headsail. Asymmetrical spinnakers are a useful addition for cruising as they are easier to tack. A short bowsprit aids their use. Both bowsprits and asymmetricals may bring penalties in race handicaps if carried with symmetrical spinnakers. The sail wardrobe should be flexible to enable different sails for cruising and racing.
It is important to have a good trailer. Trailer sailers of 8 meters in length 26.5 ft, can weigh 1.5 to 2 tonnes and a trailer another ¾ tonne. Total weight will determine the type of vehicle needed to tow them, but more importantly affect the design of the trailer. Multi-axle is common in boats over 6 metres. Smaller diameter wheels lower the trailer making launching easier but are less suited to long distance highway hauling. Trailer brakes are generally fitted to larger trailers and in some countries heavy trailers o must be fitted with breakaway automatic braking.i.e. either electric brakes or hydraulic/vacuum brakes with reservoir. These types of brakes have the advantage of remote (car) operation so that the trailer can be braked separately and before the vehicle brakes. Stopping the rig with trailer brakes on only can quickly settle down fishtailing, caused by overtaking vehicles. It is also safer to brake the trailer first on slippery road surfaces to avoid jack knifing. Electric controllers are easier and cheaper to fit to towing vehicles but electric actuators at present can only be fitted to drum brakes, whilst hydraulic systems are needed for disc brakes. Boat trailer brakes often get submerged in salt water, and corrode quickly. Disc brakes are easier to inspect as drum brakes can hide corrosion, but both types are problematic mainly because automotive components used on trailer brakes are not designed for this duty. Stainless steel has been tried for brake discs, but is not ideal for it does not disperse heat well. Some manufacturers produce aluminium bronze brake discs for boat trailers which are much superior, combined with stainless steel or aluminium bronze callipers and stainless hydraulic lines, they can be immersed regularly in seawater without corrosion. There are also now electric driven/hydraulic pump units which can be fitted to boat trailers, enabling electric control of hydraulic disc brakes.
The optimum trailer chassis material seems to be galvanised steel, which should be galvanised inside and out with adequate drain holes in all members. Aluminium has been tried but may suffer from fatigue failure . Axles and wheel rims should also be galvanised steel. Axle carriages should ideally be movable on the chassis frame to allow adjustment in tow ball vertical load for stability optimizing. The compromise is that usually for hauling at highway speeds the carriage needs to go further back, but for launching and keeping wheels out of the water the carriage needs to be further forward. Some manufacturers have developed carriages on metal rollers within the frame, so it is a matter of removal of a few pins to reverse the carriage forward before launch. Special waterproof rear lights and connectors that can be immersed are available. Wheel bearings need to be adequately rated for the load and best fitted with bearing buddies and kept regularly pumped with marine waterproof grease, not auto grease. The roller system depends on the hull shape and should support the yacht at no fewer intervals that the internal rib spacing or at bulkheads in glass boats and coincide with them. Tilt trailers can assist in keeping wheels from being submersed each time a boat launches or retrieves, but some consider that such mechanisms are not easy to make tight on the drawbar and promote side sway on the road. Rollers should be regularly inspected, without the boat. Polythene seems to be the most durable roller material with different harder grades available for aluminium. Regular maintenance is vital for boat trailers particularly at the beginning of the season and before a long haul.
Racing and ratings
If a trailer yacht is to race outside of protected waters it will require a current Rating Certificate and likely also a Safety Certificate. Even if not built to a measurement rule, the boat will need to be measured to the rule stipulated in the Notice of Race to obtain a rating (handicap). For some national, international and other yacht racing events, rules such as those of the International Racing Certificate known as the IRC or the IRC sports boat rule SBR may be specified and are examples of such rules, others exist in different countries. Note that the measurement rules are different from the Sailing Rules which stipulate how races are run and the rights of yachts in different situations.
There are other handicap systems of a simplified measurement type designed to allow very different yachts of diverse designs to compete on an equal basis. This is particularly so for trailer sailers that may race in trailer sailer fleets or in mixed fleets. In some countries a Performance Handicap Racing Fleet or PHRF may be used to rate trailer sailers, such as in NZ and in the USA and Canada In other countries, the Class Based Handicap or CBH measurement system is used for trailer sailers, such as in Australia and also in NZ
Rather than from a measurement rule, Yardstick as in Portsmouth Yardstick is used in the UK is a way of rating different classes of trailer yachts relative to each other .These are adjusted annually at a state or regional level. At a club level, starting from a CBH or Yardstick rating a Performance Based Handicap or PBH may be used, such as PBH. This attempts to measure the relative performance of a particular yacht and crew against other yachts and crews either of the same type of other type. Clubs will often run an event or season championship based only upon a CBH rating together with a handicap winner based upon a regularly adjusted PBH figure for each yacht and crew. In theory the PBH which is adjusted after each race gives each boat an equal chance of winning each race.
Clubs, classes and associations
Trailer sailers organize within sailing clubs, as separate divisions if numbers warrant or may form completely separate clubs or associations, tailoring to both racing and /or family cruising. Some popular makes or classes of yachts also form, usually in a local region, a club especially for that make of boat. Participating in such activities, as invited crew is a good way of assessing the characteristics of different trailer sailers.