Impacted bearings or corrosion in the bearings is a real concern after a nose in on land or in the water .Things you might notice in and engine with bad bearings would a whirring or whining noise while running that wasn't there before or an engine that runs much hotter than it did or should . Give the engine a good warm up and feel the case . If the areas in the front behind the prop hub are much hotter than the rest of the case chances are the bearing is failing . Spraying the engine down with WD40 after a wet crash is always good . WD40 displaces the water and does provide a little corrosion protection . There are better things to fight corrosion like CorrosionX .