It's undeniable that the warmest way to swim in the sea is to wear is to wear a wetsuit or drysuit. However, many people enjoy the sensations that you miss out on when wearing a suit, e.g. the feel of the water against the skin, the complete awareness of surroundings and the refreshingly cool temperature. Some people dislike the restrictive feel of wetsuits and find them cumbersome to use and look after.

For many, dipping in the sea all year around without a wetsuit is an enjoyable challenge t...