The sport of flatwater or sprint canoe and kayak has been in the Olympic games since the Berlin Olympics of 1932 and was a demonstration sport prior to as early as the 1924 games in Paris. The distances raced in the Olympics have changed over time, as well as the number of races permitted. Today, men race the 1000 and 200-meter distances, women 500 and 200 meters. Men and women both race kayaks, and men canoe — women’s canoe has been added to the agenda in 2020 in Tokyo. (Nevin Harrison won gold at the 2019 World Championships in the women’s 200M qualifying the US for a spot in the Tokyo Olympics!)
In a Kayak, the paddler is seated and uses a double-bladed paddle pulling the blade through the water on alternate sides to propel the boat forward. Kayaks have a rudder to steer the boat and are more enclosed with just a cockpit open. Note that it is permissible to have a cover over the cockpit called a “spray skirt.”
In Canoe events, the paddle has a single-blade and the paddler uses a more upright position by kneeling on one knee with the other leg forward and foot flat on the floor inside the boat; this creates a stable position and allows the paddler to power the boat forward by placing the paddle in the water in front of the boat and pulling the paddle down their preferred side. Canoeists specialize on a side and do not change sides during races. This style of canoeing is also sometimes called Canadian Canoeing as it was Canada that first used high kneeling techniques in international competition.
In competition the number of paddlers within a boat is indicated by a figure beside the type of boat; K1 and C1 signifies an individual Kayak or Canoe race, K2 and C2 pairs, and K4 and C4 quartets. Races are split into nine lanes with lane selection at random in the initial heats. Following the heats lane selection is then based on qualification time: 5 being the fastest to qualify, then 6, 4, 3, 2, 7, 8, 1 and 9.
More on the web –
American Canoe Association – The National Governing Body (NGB) for the US Olympic Committee. The ACA is also the NGB for slalom and para.