Rings on Honeymoon?

my jeweler offered to make me an exact fake ring to do thngs like this, although, i wear it everywhere now, on the boat swimming, my FH freaks everytime, but what the heck did we buy them for then? but I think I'm either going to have him make the fake just to be safe, or buy a fake set on my own. He did tell us a story about how a bride and groom went swimming and the water was kind of cold and her ring slipped off and it was gone.....