Arms Under and Over
The arms work together at the same time. Both arms come out of the water over the head and around in a circle – vertical to the water. The arms land out stretched on top of the water in front of the shoulders.
They now have to push down towards the toes, and when they reach the thigh, they need to come out of the water, go over the head and land outstretched in front of the shoulders.
It is similar to doing the crawl with both arms at the same time.
The central part of the butterfly stroke is the kick. A kick that requires the legs and feet to be stuck together and act like a dolphin’s flipper. The legs should work together in unison in a fluid wave like manner. In the beginning wearing flippers may be a good idea to get the feel; however, do not practice the kick holding on to a board, as this does not let the body move in the correct way for the stroke.
Rhythm of the Kick
One stroke of the arms is accompanied by two kicks. It consists of a small kick when the outstretched arms go into the water, then a large kick to push the body out of the water. At the same time of the large kick, the arms are lifting out of the water going over the head and plunging in to the water to be dragged down towards the toes.
The rhythm of small kick and big kick is the mainstay of how to swim the butterfly stroke and must be mastered fully.
The head should be kept underwater through most of the stroke. The time to take a breath is when the arms are pushing down towards the toes and almost at the thigh. This is the point the head will come out of the water and a breadth can be taken. The head needs to be back in the water immediately, otherwise, it will be impossible to continue the stroke and bring the arms out of the water and over the head.
The movement of the body is unique in how to swim the butterfly stroke, as it not only requires the legs to stay together, but the whole body rolls in a fluid wave with the arms and two kicks making it possible to move forward. Very similar to the way a dolphin leaps out of the water. It takes practice to master, but it is also important to be relaxed in the water and try out the moves. Tension will only inhibit the freedom and fluidity required by the butterfly stroke.