[takeshi]

I think 3mm will be fine. I was in cuba in january and used a 3mm suit. It was yamamoto neopren with open cell interior. I was comfortably in the water for at least six hours. Slickskin or open cell interior is warmer, smoother and in my opinion more comfortable to wear. Nylon is more durable. At least with open cell you need to use soap or some lube to put it on.