I'm not a fresh water guy, but know a bit about hunting in the water.
If you can find a beach... you know, the kind where mom lays in the sun while the kids play in shallow water? Here's how it works:
Mom arrives at the "towel line" and puts sunscreen on the kiddies and herself... all the time wearing her wedding rings. Sooner or later, she's going to venture into the water to either cool off herself or yell at little Billy for trying to drown his sister. :lol:
Remember that sunscreen? Well, it makes her hand slippery. Combine that with the cooler water causing a slight shrinkage of her fingers and you have "a perfect storm"... that ring stands a pretty good chance of coming off (un-noticed) in the shallow water.
So, if I'm looking for jewelry (who's not?), I'll pick the shallow water just off a sun-bathing beach every time.