Obstruction in open-water swimming occurs when one swimmer obstructs another swimmer by interfering with them, bumping into them, or pushing them with their arms, legs, or shoulders.
Rules of racing do not permit such interference since it is unsafe and unfair. Blocking others may be penalized through additional time or disqualification, depending on the severity and the individual’s intent. Swimmers must be prudent in crowded start waves and while turning at buoys so as not to strike others accidentally. Practicing how to sight and draft effectively enables swimmers to avert collisions and reduce the possibility of getting in another’s way or accidentally blocking them in choppy sections of the race.
