Look carefully at the grip panels. You'll notice that the left grip panel shows good detail while the right grip panel shows considerable wear at it's lower end. This tells me that it was once a duty gun that an officer carried while often wearing a waist-length jacket, they type that troopers and motorcycle cops wear. It was the constant rubbing of the jacket that caused the uneven wear on the grips.

While it may have been stored on a boat, I'm more inclined to think that this old baby saw lots of holster time. It's a good find and certainly worth a restoration. Many guns are carried a lot and shot a little. I'm willing to bet that this gun is mechanically tight.