1. Start — The swimmers shall line up in the water facing the starting end, with both hands
placed on the gutter or on the starting grips. Standing in or on the gutter, placing the toes
above the lip of the gutter, or bending the toes over the lip of the gutter, before or after the
start, is prohibited.
2. Stroke — The swimmer shall push off on his back and continue swimming on the back
throughout the race. Some part of the swimmer must break the surface of the water throughout
the race, except it is permissible for the swimmer to be completely submerged during
the turn, at the finish and for a distance of not more than 15 meters (16.4 yards) after the
start and after each turn. By that point, the head must have broken the surface of the water.
3. Turns — Upon completion of each length, some part of the swimmer must touch the wall.
During the turn the shoulders may be turned past the vertical toward the breast after which
a continuous single arm pull or a continuous simultaneous double arm pull may be used to
initiate the turn. The swimmer must have returned to a position on the back upon leaving
4. Finish — Upon the finish of the race, the swimmer must touch the wall while on the back.