The first boat to cross the finish line without any penalties is the winner of the race. The finish line has been cleared once the bow of the canoe or the kayak has crossed the line, marked by a pair of red flags on either side of the course.
Olympic races use a mechanical starting gate, which is anchored to the lane buoy cables and floats underwater. To begin a race, the starter says, "Start within ten seconds," and those words are followed by a sound from the starting system. If a competitor starts to paddle after the voice signal but before the sound signal, the athlete is given a warning and all competitors start again; two false starts by the same boat results in a disqualification.
To prevent boats from riding each other's wakes, a boat may not come within five meters of a boat next to it. If this occurs, the course umpire, who is following the competitors in a motorboat, gives the boat in violation a red flag. The competition committee then decides whether the boat should be disqualified. Accordingly, a boat that fails to stay in its lane is disqualified.
If a boat capsizes, its competitor or crew is disqualified.
As competitors paddle down the course, they must negotiate a series of 18 to 25 gates that are strategically placed throughout, similar to a slalom course in alpine skiing. Of the 18 to 25 gates, a minimum of six are marked as upstream gates, requiring paddlers to negotiate them in an upstream direction. The remaining gates are to be negotiated in a downstream direction.
Each gate is marked numerically, and a competitor must go through the gates in the order they are marked. Gates consist of two suspended poles, measuring between 1.4 and 4 meters in width. A competitor can identify if the gate is an upstream or downstream gate by its color: Green and white-striped delineate downstream gates and red and white-striped delineate upstream gates.
In order for a gate to be cleared, the competitor's head must cross the line between the poles in accordance with the correct side of the gate and the course plan. In the C2, both competitors must cross through on the proper side.
Certain errors during the negotiation of a run result in seconds added to the final score. Judges signal these errors by holding up yellow discs with either the number "2" or the number "50" on them, signifying the number of seconds penalized.
A competitor touches one or both of a gate's poles (maximum one penalty per pole)
Failing to pass through a gate. If a competitor fails to pass through a gate, he or she has the option of going back and making a second attempt at clearing the gate, or taking the 50-second penalty. However, competitors start courses in three minute intervals, so if a competitor decides to go back an attempt a gate, it is possible that the next boat could overtake the first one, in which case the second boat has right of way.
Touch of the gate without correct negotiation.
Intentionally pushing a gate to allow negotiation.
The head of the competitor (or one of the competitors in C2) is submerged while passing through a gate.
The total score is calculated by combining the total running time and the penalty seconds. The competitor with the lowest score wins.