For years we fished with multipliers in our local waters, including some folks using just that model. We would fish in the ocean with the reel nearly permanently under water on some occasions - never a problem provided the reels were given a good wash down with fresh water after the event, and left to air dry. The only real problem came for folks that didn't wash their reels, was that the soft metal shields inside the bearings would corrode and seize the bearings.
Wash with clean water, get rid of all the salt residue, and air dry...……… then go fish.