Stroke & Turn Summary
Potomac Valley Swimming (http://www.pvswim.org/official/stroke_brief.pdf)

Freestyle: Forward start. Head must surface by 15-meter mark. Some part of swimmer must touch wall at turn and finish. No pulling on lane lines, walking or pushing forward off bottom.

Backstroke: Head must surface by 15-meter mark. Shoulders must be past vertical toward back throughout race except at turn. Shoulders may turn past vertical as part of a continuous turning action at the turn only. Continuous single or simultaneous double arm pull may be used to execute turn, any kicking or gliding must be part of the turning action. Swimmer must be past vertical toward back when he/she leaves the wall. Swimmer must remain on back and may not be completely submerged except at touch at finish.

Breaststroke: Forward start. Swimmer permitted one full arm pull (beyond hipline) and one kick while submerged at start and after turns; head must surface by the widest part of the 2nd stroke (before hands turn inward). Arm pulls shall be in same horizontal plane (parallel to water surface). Hands shall be pushed forward from the breast on or under the water (elbows must remain in water except at turn or finish). Stroke cycle consists of one arm pull and one kick in that order; the head must break water surface at least once each cycle. Swimmer’s leg motions must be simultaneous; feet must be turned out in downward propulsive part of kick. No flutter or butterfly kick is allowed. On the turn & finish, a simultaneous two-hand touch is required. On turn, shoulders must be past vertical toward the breast when swimmer leaves wall.

Butterfly: Forward start. Swimmer is allowed one arm pull and as many kicks as desired at start and turn, but head must surface by the 15-meter mark. The first arm pull must bring the swimmer to the surface. Arms must pull and recover simultaneously, with forward arm motions on or over the water surface. Up and down movement of legs and feet must be simultaneous. Breaststroke or flutter kicks are not allowed. At the turns & finish, both hands must touch simultaneously, but do not have to be on the same level. At the turn, shoulders must be past vertical toward the breast when swimmer leaves the wall. IM: Butterfly, back, breaststroke, and free in that order. When changing from one stroke to another, the touch must conform to the finish rules for the stroke just completed.