Watch the cold
Hypothermia can be a risk. Listen to your body and if you start to feel cold, get out of the water. You also need to be wary of sunburn and use a high-factor waterproof sunscreen on areas such as neck, shoulders and the backs of your legs. Dehydration is another consideration, particularly in sunny and/or warm conditions – you may be in the water, but you still need to drink regularly. For longer swims you may need to apply Vaseline to areas of possible chafing, especially if you’re wearing a wetsuit. Even without a wetsuit, you should apply Vaseline around the edges of your swimming costume, under your arms, at the bottom of your swimming cap, etc.
Most people graduate to sea swimming from the pool, so it’s important to be aware of the differences between the controlled environment of a pool and the natural environment of the sea. The lack of guidelines or lane ropes to keep you on course, and the fact that weather and swimming conditions can change in minutes, can take time to adjust to.