If you happen to find a huge flat smooth area that you never saw before, detect find target. But don't dig (mark area with a flag) Then in the spring come back with scuba gear.
Luck would have it, I just thought it up, and not something I had expericed first hand. It just poped in my head, and it seemed funny, but at the same time, it could happen to someone if they was lets say off their game a hair, from being drunk, out detecting, or what not. Maybe they thought salt flats apear in the mountians at certian times of the year. lol