The technical rules for butterfly are found in Article 101.3 of the rulebook.

Your responsibility begins as the swimmers enter the water after their forward start. Other than during the turn, the athlete’s body must be on the breast for their entire swim. The best position to observe a butterfly race is slightly behind the slowest swimmer with a clear view of all the assigned lanes.

After the start, the swimmer is allowed one or more leg kicks but only one arm pull under the water. This arm pull must bring the swimmer to the surface, with the head breaking the surface of the water at or before the 15 meters mark. The swimmer must remain on the surface until the next turn or finish.

The arms during the butterfly are simultaneous at all times. Both arms must be brought forward simultaneously over the water and then pulled back simultaneously under the water throughout the race. Simultaneous and symmetrical are not the same and symmetry is not required.

All up and down movements of the legs and feet must be at the same time. One foot may be higher than the other, but cannot be alternating. The official must observe alternation, it is not enough to see the left foot higher at one point and then the right foot at another. A scissors kick or breaststroke kick is not permitted.

At the turn, the swimmer should touch the wall with both hands separated and simultaneously at, above, or below the water level. It is important that you observe the touch carefully. Many swimmers touch the wall very quickly with both hands and then one hand will immediately leave the wall. As in breaststroke, as long as the touch was simultaneous, this is legal. You need to actually observe the swimmer not touching simultaneously to signal an infraction.

After the touch on the wall, the swimmer may turn in any manner. Their body must be on the breast when leaving the wall. To determine if the swimmer’s body is on the breast, observe the relative position of the upper shoulder to the lower shoulder. Sometimes the distortion from the water and the movement of the water can interfere with an observation. When the swimmer leaves the wall, the official should watch the feet leave the wall and then check to see if the proper body position has been attained.

Each backwards pull must be followed by an overwater recovery. The break of the elbows indicates the start of the next stroke. Sometimes a swimmer will miscalculate their distance from the wall and make an underwater recovery to make up the distance. These swimmers are in violation since their backward pull is followed by an underwater recovery. This is not legal.

Think about an airplane, a boat and a submarine. An airplane is completely above the water, a boat skims over the water and a submarine is completely submerged. The arms during an overwater recovery must be like a boat or an airplane. If they are a submarine, they are not legal.

The swimmer must touch the wall with both hands separated and simultaneously at, above, or below the water level. The hands do not have to be on the same plane. One hand can touch above the water and the other below, as long as the touch is simultaneous.

To review, the rules require:

● Swimming on the breast

● Head breaking the surface at or before the 15 meter mark after the start and turn

● Use of butterfly kick with simultaneous movements

● Arms must recover over the water and move simultaneously throughout

● Touching the wall after each length and at the finish with both hands separated and simultaneously

Remember - if you're not sure what you have observed, the benefit of the doubt always goes to the swimmer.

What are some of the common infractions that warrant a disqualification?

Let’s take a look at typical rule violations for butterfly.

For butterfly, typical rule violations are:

● Head not breaking the surface by the 15 meter mark after the start or turn

● Movements of the arms, legs, and feet that are not simultaneous

● Touching the wall at the turn or finish with one hand or not simultaneously

● Underwater recovery

● Leaving the wall after the turn past vertical toward the back

If you observe any of these in your jurisdiction, raise your hand to signal an infraction.