A friend of mine carried his Olympus OM10 in a sailing boat for a half day trip close to the shore (South Atlantic), looking for whales near Puerto Madryn.
The camera was in it´s 👎ever ready case, and as far as he can recall, no sea water got into the camera, however, the camera failed to work the same day after shooting a 36 exp. roll.
All electrical contacts inside the camera, either printed circuit or finger springs were corroded beyond repair.
IIWY, I´ll pick another camera. A purely mechanical one (no electronics of any kind inside) will withstand better the harsh environment of a sailing boat, or better a simple splashproof P&S.
Ernesto