Water "resistant" is not waterproof. I would not use that on deck
underway. I got crap at the Apple store because my iPhone
had salt water corrosion
without ever getting wet. It stays in a dry bag when underway, but i use it at anchor
or docked. The Apple "genius" asked me "do you spend a lot of time by the ocean." Like it was a crime. I answered "Seriously? You know we are in San Francisco
right? Surrounded by salt water
on three sides? Are we ever NOT near the ocean?" They should call it the pompous dork bar not the Genius Bar.
End of rant. My feeling is: If it can't swim it has no business being on a boat!