Though most open water races do not require a specific stroke, most competitors employ the crawl stroke also known as freestyle. The efficiency of this stroke was demonstrated by Gertrude Ederle, who, as the first woman to swim the English Channel, employed it to demolish the existing world record by more than 2 hours.
When covering large distances, swimmers may head off course due to current, waves, wind, and poor visibility. Typically, buoys are stationed periodically across a large expanse to provide guidance. However, buoys are often invisible due to interference from choppy water and reduced visibility through goggles. Swimmers are encouraged to 'triangulate' by looking for two aligned, easily visible objects on land that are directly behind the destination (such as the end of a pier as it lines up with a hilltop), and to make sure they continue to appear aligned during the race.
Drafting, which is prohibited by some race regulations, is the technique of following another swimmer so closely that water resistance is reduced. When swimming closely alongside or behind a swimmer in the lead swimmer's wake, resistance is reduced and the amount of effort to swim at the same speed is correspondingly reduced. In calmer conditions, or when facing surface chop, swimmers can also significantly benefit from swimming immediately behind or closely alongside a swimmer of comparable or faster speed. Not all race organizers permit drafting, and swimmers can run the risk of disqualification if they are caught.
When entering the water, swimmers can use techniques to take advantage of the shallow water. One such technique is walking along the bottom. Another technique is "dolphining", which involves diving down to the bottom and launching oneself upwards and forwards. This technique can also help to avoid incoming waves. When exiting the water, swimmers can body surf to take advantage of waves.