The official boats recognised by the International Canoe Federation (ICF) as ‘International Boats’ are the following: K-1, K-2, K-4, C-1, C-2 and C-4, where the number indicates the number of paddlers, “K” stands for kayak and “C” for Canadian or Canoe, depending on location. Kayaks have a steering rudder, which is operated by the (foremost) paddler with his feet; in a kayak a paddler is sitting, while in a Canoe he is kneeling on one knee. The ICF rules for these boats define among others the maximum length, the minimum weight and the shape of the boats. For example, by ICF rules, a K-1 is at most 520 cm long, and weighs at least 8 kg for marathons, or 12 kg for sprints. In 2000, after the Olympic Games in Sidney, the ICF withdrew width restrictions on all boats, spurring a fury of innovations in boat designs. Modern boats are usually made of carbon fiber and/or aramid fiber (e.g. Kevlar) with epoxy resin.
In Canada, a racing class exists for the C-15 or WC or “War Canoe”, as well as a similarly designed C-4 (which is much shorter and more squat than an ‘International’ C-4). An antiquated boat class is the C-7, resembling a large C-4 which was debuted by the ICF with little success.
Paddles for propelling are double-bladed for kayaks, and single-bladed for canoes, and are usually made of carbon fiber with epoxy. For kayaks so-called wing paddles are generally used, the blades of which are shaped to resemble a wing. These paddles are more efficient than traditional paddles, presumably because they create extra “lift” in the direction in which the kayak moves. The wing blade has undergone many evolutions in the past two decades, evolving from a flatter blade to one with a more pronounced curve to better catch the water. For racing canoes, the blade will typically be short and broad, with a ‘power face’ on one side of the blade which is either flat or scalloped out. The shaft will typically be longer than a tripping canoe paddle, because the kneeling position puts the paddler higher above the surface of the water. More recent designs of canoe racing paddles will often have a slight bent-shaft (a concept conceived by Gene Jensen in the 1950s), but not to the degree used in marathon paddles. Many high-performance canoe paddlers prefer the feel of a carbon-fibre shaft mated to a wooden blade, while nearly all high-performance kayak paddlers use paddles made completely of carbon fibre.