Another stroke is the same positions for the arms as the plain back stroke combined with the leg drive of the crawl. Still another is the same, except that the arms move alternately as in trudgeon stroke. _Floating._--In order to float on the back, the balance of the body must be determined; hence it is often necessary if the feet sink to throw the head back and raise the arms over the head. In some cases, if the legs are bent, it helps the balance. After practice, the swimmer soon learns to float. Short breaths, keeping the lungs as full of air as possible, are better than long ones. _Plunge for Distance._--In reality this is floating with the face flat down in the water. The first part of the plunge is the dive, which gives the impetus. The dive taken is the shallow dive. As the breath is held from the minute the head enters the water until the plunge is finished, it is necessary that the lungs be well filled. After the body is in the water, the muscles should be relaxed, and the swimmer should keep the air in the lower part of the lungs. The plunge should be as straight as possible; the direction may be changed by moving the arms (which are stretched straight out in front) or the head in the direction desired. This motion should be slight, as the least friction impedes progress, and distance is the desired result. Diving As diving is a very large subject, it is impossible to give in detail all the varied dives. There are three important dives everyone should know--the front, back, and shallow or racing dive. The beauty of diving is in the form. _The Front Dive._--The diver stands erect at the end of the spring board, falls forward, then as the body passes the balance point, the arms are raised straight over the head, knees bent; then spring out so that the body is parallel to water, arms above head; the body is curved downward and enters the water, arms, head, body, and legs forming a straight line. In springing, jump out parallel to the water. The running dive is very similar. _Back Dive._--The diver turns with back to the water, heels over the edge of board into space; the arms are over head, body is curved backward; as the balance point is reached, spring out, turning body as it enters the water. The position of the head is important. Ducking the head or throwing it too far back, added to stiffness of the body, makes the dive awkward. The legs should never be apart, but together; toes pointed, so that feet are not flat; the fingers should be together. The shallow dive, known as the racing dive, is important for those interested in speed swimming, as is the racing turn.