dry suit
A dry suit is a diving suit similar to a jumpsuit designed to protect the wearer from exposure underwater.
In contrast to a wetsuit, which allows water through, a dry suit is meant to maintain a watertight environment for the wearer. As such, a dry suit is baggier and is often not skin-tight. It insulates the wearer better than a wetsuit and so is more suitable for cold or deep water, not so much for beach recreation.
This tag implicates diving_suit (learn more).