If calf cramps occur while swimming, first of all do not panic, stop the leg movement immediately, stand in place using the leg muscle on the side where the cramp occurs, bend the toes upwards and stretch the foot, wait until the cramp is relieved, walk slowly towards the pool, massage or apply a hot compress to the local muscle after going ashore and take rest.
Remember not to engage in any further strenuous activity that day to avoid a recurrence of calf cramps.