4.1.1 RegulationsThere are regulations concerning maximum length, minimum width and minimum weight of boats. There are also regulations concerning the amount of buoyancy (air bags) fitted into a boat. Check the BCU Wild Water Racing Rules and ICF Rules to confirm the regulations in force.
4.1.2 Hull Shapes
Modern racing boat hull shapes are all very similar now. However there are subtle differences which affect the handling of a boat.
Most modern boats have an elongated teardrop shape at the waterline (think of the shape of a tadpole). The hull then expands rapidly upwards and outwards above the waterline. This introduces volume when a boat starts to pitch and thereby keep the boat flatter (and moving faster).
The main differences concern the amount of rocker in the boat. Rocker is the curve of the hull from bow to stern. It is most easily seen by placing the hull on flat ground and seeing the rise of the bow and stern from the ground. Generally the greater the rocker the easier the boat is to turn, though it can become ‘skiddy’. The less the rocker the more the boat will hold its line and track. There can be different amounts of rocker at the front and back of a boat.
Modern flatwater racing boats have a surprisingly large amount of rocker. This is so the boat generates lift and, in fact, rises out of the water, thereby reducing the wetted area of the boat and hence the resistance of the boat. It’s uncertain whether WWR boats are moving fast enough for this principle so it’s probably simpler to consider rocker just from the handling point of view discussed above.
4.1.3 Fitting OutAttention to boat fittings is not just for the elite athlete, the beginning racer will benefit from the control and power. Being in an ill fitted boat is similar to trying to drive a car fast down the motorway with a loose steering wheel - you have to make large correction movements before something happens.
188.8.131.52 Importance of fittingsBoat fittings are designed to address two key requirements:
Applying power to the stroke, allowing a dynamic and free paddling position
Maintaining control of the boat, over leans and pitch etc.
At the extremes these two requirements are contrary, a very free paddling position will offer little control and a very tight fitted boat with great control will offer little in the way of dynamic paddling support.
Although there are some key principles of boat fitting, each person is individual and will develop personal preferences over time.
184.108.40.206 Kayak fittingsThe key to optimal boat fitting is to reach a compromise where the athlete can drive dynamically with the legs, gain a full rotation of the pelvis to initiate the paddle stroke and yet still offer control over the lean of the boat. In white water, there are very few 'pure' paddle strokes where the application of power has no steering component. Thus the athlete needs to make sure that they can control leans and still drive powerfully with the legs.
The key principle is the fittings should be set up so that there is always three points of contact at any point in the paddle stroke, this allows the paddler to maintain control over the direction and lean of the boat even if a dynamic leg drive is being used.
1. Footrest - must be solid bar or plate across the whole width of the boat. The feet are used to assist in steering, and so need to be able to reach to the side of the boat, but should be kept in the middle of the boat for normal paddling. When the feet are at the edge of the boat this locks out the hips and makes rotation more difficult, and also introduces a torque to the paddle stroke which causes 'boat waggle'. The footrest should be set up close enough to keep the athlete in the seat, and allow a strong leg extension. Typically this is actually feels quite tight, a footrest that is too loose allows the athlete to slide down the seat, inhibiting rotation - or requires the paddler to brace too much to get purchase on the thigh braces.
2. Thigh braces - The braces (or bars) should be set up to be in contact with the thigh at the hip, and then follow the angle of the leg when braced. The fittings should allow the knees to be held relatively close into the middle of the boat for normal dynamic paddling, but have the option to move wider if necessary. The key is the height at the hip - it should be tight enough to allow the leg to be relatively relaxed and still maintain control. Be aware that the knee needs to lift up and drive forward in order to allow the pelvis to rotate, and so any fittings need to permit this.
3. Seat - Ensure that the seat is fitted close to, or on, the bottom of the boat, and is blocked out to the sides and front/back. A high seat will be more unstable than a low seat. Seat design is a personal preference and can make the difference between a fun paddle and a raw back. Once you have found a seat design that you like - keep with it. Seats can either be high back or low back (traditional) - traditional seats require the addition of a backstrap to ensure a solid paddling platform. Ensure that this backstrap is snug, and very smooth to reduce chafing. Ensure that the seat allows you to 'spin' within it to allow hip rotation, and that blocks are placed each side above the hips to remove any lateral play. The seat should have a little lean forwards to tilt the pelvis and assist in rotation. The feeling you want to achieve is being able to spin, without moving up out of the seat, or moving from side to side.
When fitting out a boat make sure that you are wearing the same clothing you will be using to paddle in, as the thickness of the material will have an effect on the tightness of the fittings.
If you paddle in a shared club boat, try to ensure that the fittings (footrest, seat, backstrap and thighbraces) achieve a good fit for each athlete.
220.127.116.11 Example kayak fittingsThrough all of the following you will find reference to measuring and recording. This is important in ensuring that subsequent boats of the same design will be fitted out identically.
The starting point – original fittings in old boat…
| The target – a new boat of new design….
If you have the same design of boat for practice and race, ensure that both are set up identically. This ensures that both boats will perform the same way and transition from practice to race boat is seamless. Typically the seat will make a big difference to the feel of the boat – and so taking a primary seat from one boat to another is a way of reducing the amount of variation in feel between the boats. In these examples the seat is swapped from the old boat to the new – and provides the reference for all the fittings. However a new seat of exactly the same design can also be used (make sure the tilt and fitting of support foam is the same as the old seat).
18.104.22.168 Installing the SeatWhen you find a comfortable seat design, stick with it. The seat should allow rotation, but provide a secure paddling platform. Make sure the back is well supported to provide lower back/pelvis support and allow good leg drive.
The seat should be comfortable and snug. Ideally the seat shape will fit the athlete’s bottom shape, but if the bottom is too slack, then foam pads should be added to make it snug all round. A backstrap is important as it provides an extension to the back of the seat that moulds to the back flexibly when the body is moving around. The backstrap anchor points should be far enough forward on the seat to allow the backstrap to hug the back as much as possible. The seat is best mounted on flanges in the side of the boat. Seats attached to the bottom of the boat risk being dislodged when running over rocks. If a seat is floppy and poorly fitted, controlling the boat will be very difficult.
Sit in the boat and adjust the position of the seat for height from the hull and the angle of the fore and aft rake for the most comfortable position and one which will give the correct trim when in the water.
|Height of the nose or point of the seat from the hull|
Height of the back of the seat from the hull
|Distance of the seat from a reference point, e.g. the rear of the cockpit or bow of the boat|
|Square angle across boat for seat.|
|Write these down somewhere safe.
A garage wall is ideal
These dimensions will ensure that the seat is always in the same location and attitude.
Ensure that the seat is firmly fixed, either epoxied or screwed into place. Fit high density foam to block the seat and stop any flexing of the seat at the rear or the side. Bracing either side of the centre point allows a little flex where the coccyx touches the seat, reducing chafing.
Ensure that the seat is as close to the bottom as possible – a high seat is more unstable than a low seat.
22.214.171.124 Installing the footrest
The footrest should be a comfortable distance away, which allows for a leg position similar to a flatwater boat but with the knees slightly parted. The footrest should be a bar across the full width of the boat to allow the feet to be central but also to allow the possibility to slide sideways the whole width of the boat. Some athletes prefer a wooden bar footrest to allow the ball of the foot to slide up and down slightly when the heel of the foot is moved in or out slightly.
The form of the footrest is down to personal preference, from wooden bar to carbon tube. The principle for installation is similar.
Sit in the boat and wedge your intended footrest at a position which is comfortable.
Make sure that you wear the type of shoes that you will be using when paddling, different shoes could add more than a centimetre and start to push you to the back of the seat.
Measure the distance from the bow to either side of the hull and mark the position on the hull to ensure that the footrest is square on.
By shining a light from the outside of the boat it is possible to accurately position the footrest inside the boat.
Write down the dimension (on the garage wall)
Measure the height of the footrest from the hull. A good idea at this point is to make a height template (a piece of wood of the correct length) so that when the footrest is removed form its temporary position relocation for height is simple.
When using tube for a footrest, aluminium or carbon paddle loom, cut this a little short (2 mm either side) and stuff in firm ether-foam. before wedging it back in place. This will allow some flexing of the hull if you hit something side-on and minimise the chance of punching a hole in the side. Also, if you should need to reposition the footrest, you only hacksaw through the tape and foam and not the tube as well.
Clean the area to be fixed and if necessary abrade the tube lightly with 180 SiC. A mixture of glass and Kevlar tape is probably best for installation, ensuring that there is sufficient to prevent detachment in time of crisis. Bear in mind that the crucial bit is the first layer. Several layers will not necessarily improve the strength but will add weight.
Weigh all the resin and materials as they are used. Record the information. Fittings will normally add approximately 500g over the weight of a boat + seat – if they weigh more, think how could you reduce this weight?
126.96.36.199 Thigh Braces
Having fitted seat and footrest in the correct position it is time to turn attention to thigh braces.
Thigh braces are important to give further refined control, including lifting the bow and holding leans. The bars should pass over as much of the thigh (rather than the knee) as possible. They should be positioned so that on flatwater the thigh braces are just brushing the thigh. The athlete can then tighten their legs into the thigh braces by simply sliding their heels back and shortening their leg length, thereby raising their thighs into the thigh braces. The relationship between footrest position and thigh brace position is therefore important. The thigh braces should be positioned to encourage as narrow a leg position as possible when on easy water but allow for a slightly widened leg position in rough water.
There are various designs and preferences. In all instances make sure that they are strong enough and securely fitted. Should they fail at a crucial moment it could result in a capsize.
Sit in the boat and fit the thigh braces around you, packing them into position with tape and foam. To ensure good contact cut the bars to fit the contours of the hull. Mark the position for fixing onto the boat, if possible measure the location and record for reference.
As with the footrest, epoxy well into position. Weigh the thigh bars, resin and fabric and record it.
You will now have a well-fitted boat, which should be comfortable and an efficient means of energy transfer. (note this example shows an old seat being installed - this normally would be a new seat)
By recording all of the information as you progress, fitting out the next boat (of the same basic design) will rely on a minimal amount of trial and error. If you find it necessary to change the position of any of the bits, record the information.
If all your boats are fitted identically, the transfer from practice to race boat becomes seamless and paddling will improve in the knowledge that equipment is at its optimum.
Expect to take 1 day to fit out a single new boat, up to 2 days to fit out a new design of boat. Check and re-check the fittings and feel against existing fittings – and only fix in place when you are sure. If you can find an assistant with excellent glassing skills – this also helps!
4.1.4 TrimmingA boat should be trimmed to gain maximum performance from the hull shape. The general goal is to have the boat flat trimmed or slightly bow light when moving at race pace. For this to be the case on flowing water, the boat usually has to be set to be a little more bow light when paddling at race pace on flat water.
How bow light to make the boat depends on the hull shape. Having a boat set slightly bow light usually makes for easier steering as the bow does not ‘stick’ in the water. Sometimes the aim of setting a boat bow light is also to set the stern deeper to overcome too much stern skid. If an athlete is trying to overcome this problem, perhaps changing to a hull design that has less stern rocker may be a better solution.
4.1.5 ProtectionRacing boats are moderately expensive but their life can be extended by using protection when practising.
Guards can be made to fit a boat, usually to the stern and bow. Some boat manufacturers sell ready-made guards for their boats. Guards, particularly on the stern, need to be well attached with tape as it is easy to scrape them off. The negative aspect of guards is that they change the performance and steering characteristic of the boat. This can cause more rock hits due to the lack of control an athlete has. Too often athletes train with guards and remove them for the race only to find the boat handles completely differently.
Other material such as lino can be used as a guard. A heavier tape-like material known as Action Patch affords very good protection, but once applied it may not be possible to remove it, so is only really suitable for boats intended for practice only.
Whilst affording less protection, simply using duck tape (or carpet tape) is a better compromise. It protects from bumps and scrapes, though not from heavy hits. However, when not scraped or torn, it has minimal effect on the performance and handling of the boat.
4.1.6 RepairsA modern racing kayak or canoe is remarkably resilient to damage, and it’s lifespan will be greatly enhanced by repairing damage as soon as possible. Often at races it is not practical to repair the boat so gaffer or duct tape is used to protect the damage until a sound repair can be undertaken at home.
In all cases it is best to ensure that the boat to be repaired is fully dry, clean and the damaged area has been masked off to ensure there are no unexpected dribbles of resin onto the remainder of the boat.
Minor damage to the boat, cracks in the gelcoat etc can and should be repaired from the outside by applying a little epoxy to the damaged area to allow it to re-wet out. Warm epoxy will flow better than cold to seep into cracks.
Major damage to the stern is the most common in a WWR boat, and will often require a repair from the inside to recreate a good approximation to the original shape.
4.1.7 Bow RepairsOne of the most common repairs that need to be undertaken to a racing kayak or canoe is to repair the bow after a head on collision. Without repair to the bow, over time it will become weakened and ‘fat’. This will often require more radical repair from the inside to strengthen fully.
For minor repairs to the bow, cut all loose material back from the damaged bow. Mask off closely to prevent drips and to allow a fine and accurate finish. Tease apart some Kevlar cloth or tape to create some Kevlar string or rope of approximately the correct length – cut slightly over length to ensure you have something to hold onto. Fully wet out this small rope section – and then carefully apply to the damaged bow section making sure it is well bedded in (use latex gloves to allow you to use your fingers). Roughly shape to the correct curves of the bow and allow to cure.
When the epoxy is cured, remove the masking tape and cut back the excess rope. Allow to fully harden
When fully hardened, roughly cut to shape with a Stanley knife, and then sand back to an accurate shape. Work down through the wet and dry grades (use wet to stop the Kevlar from going ‘furry’) and finally finish with t-cut or similar cutting paste to give a fully polished finish.
You should now have a bow which is shaped pretty closely to the original, and being made of solid Kevlar it will take a few knocks.