There are 3 basic styles of closed boats used in slalom whitewater competion. There are strict requirements for length, width and weight at major international competitions, as well as requirements for nose and tail shape (limits to how pointed they can be). Finally safety requirements are such that grab loops must exist at the front and rear of the boat, either on the upper or lower surface. In addition personal safety equipment (buoyancy jacket, protective helmet) are required.
Summary, Per ICF 2009
Minimum Weight of Boats:
During the weighing process, residual water must be removed from the boat.
Boat Dimensional Specifications
All boats must have a minimum radius at each end of 2 cm horizontally and 1 cm vertically.
Rudders are prohibited on all boats.
Boats must be designed to, and remain within, the required dimensions.
Personal Flotation Device/Life Vest/Buoyancy Jacket
A buoyancy jacket (buoyancy aid) shall consist of non-absorbent flotation material equally distributed, front and back, in a jacket or vest worn about the upper torso. It must have buoyancy sufficient to float a 6 kg legalised lead weight or its equivalent in other metals, and should be designed to keep a conscious person floating in a face-up position in the water.
The safety helmet must offer sufficient protection to the head of the athletes in case he/she hits a rock for instance (Space between head and helmet shell to absorb the shock) and a solid chin strap.
Minimum Length: 3.50 metres Minimum Width: 0.60 metres Minimum Weight: 9 kg.
Competition kayaks are made of a combination of kevlar and carbon usually. They have foot pegs as well as thigh supports to allow the paddler to brace while executing turns, driving the paddle hard, or rolling. Normally a molded kevlar/carbon seat is mounted to side flanges inside the boat. The racer uses a double bladed paddle of carbon fiber that can have either a straight or 'bent' shaft as shown above.
Minimum Length: 3.50 metres Minimum Width: 0.65 metres Minimum Weight: 10 kg.
Likewise canoes are made of kevlar and carbon. Unlike kayak paddlers, the canoeist must kneel while sitting on a low foam block. He or she use a single bladed paddle. In order to hold the competitor in the boat during manoevres or rolling, they will outfit the boat with either quick release straps over the thighs, or have knee pockes carved out of a foam bulkhead in the boat. A specific skill required for this paddler, is that they must paddle well on both sides of the boat, without switching hands. This indeed looks awkward to the spectator, but enables this boat to turn on a dime. The C1 uses a different technique to roll it than the kayak.
Minimum Length: 4.10 metres Minimum Width: 0.75 metres Minimum Weight 15 kg.
These boats are longer and heavier, in order to have enough volume and strength for two people. The front and rear paddlers paddle on opposite sides of the boat. Occasionally the front paddler will cross over to help carve a turn. This class requires a high level of coordination to maximize speed and turns. Likewise, rolling a C2 is more complicated that the single boats due to the timing.