Line of sight is how well the swimmer is able to see and target something distant, such as the turn buoy or finish arch, without anything obstructing the vision. Having an unobstructed line of sight is key to swimming well and conserving energy while swimming in open water.
Sighting is where the swimmers momentarily look upwards to verify whether they are swimming in the correct direction. The view can be obscured by waves, sun, fog, or other swimmers, which makes turning knowledge essential. Having good vision and frequent sighting assists the swimmers to swim in the correct direction and conserve energy.
