noun - Swim cap (or swimming cap, bathing cap, bubble cap, neoprene cap or dome swim cap) is a silicone, latex or lycra cap worn on the head by recreational and competitive swimmers, both in the pool and open water.
Swim caps are worn for various reasons. Some facilities require the wearing of swim caps, in order to protect filters from becoming clogged with loose hairs which fall from the head of swimmers who are not wearing a cap. Caps are also sometimes worn in an attempt to keep the hair relatively dry or free from chlorinated water, to keep the sun off the hair, to reduce drag in the water caused by loose hair, and to keep the wearer's head warm.
A swim cap tan is the division on a swimmer's forehead between the skin of pronounced paleness relative to the rest of their face that has been suntanned by prolonged exposure to ultraviolet radiation in a pool, outdoors or in the open water. It is caused by wearing of a swim cap on the head while swimming outdoors.
The young woman always wore a swim cap during her pool and open water swimming workout.