Image from outside would help as well to be honest. The picture you have posted shows no obvious issues. Apart from possibly you have a second floor overhang, provided using correct roofing thatch pieces, and it is above sea wave max level then should be fine.

I have some docks, and in storms the sea washes over them a great deal, you are on an island end, maybe, it is just too low and bad weather rises water enough to flood the ground floor.