Wetsuit
Unless it’s a really hot summers day you should wear (or bring) a wetsuit.
Wetsuits are better than drysuits because they have a wider temperature range. It will keep you warm and it will add padding protection.
A long wetsuit (full arms and legs) are best as they will protect and warm you the most, but it’s up to preference, as some sailor’s prefer the short wetsuit and wear it all year round.