I would think at ten foot underwater it is water resistant. The excal is 200ft and as such is waterproof. As a diver it used to be watches were water resistant and or water proof. A watch was waterproof if had a depth rating of 660 ft. Anything less was water resistant. Most watches today are 3 atm or approx 100 ft. Somehow i just cant trust a machine that is not waterproof.