I met two guys at the lake and swam out with them to the bouy spot. They were not students..one guy was an environmental scientist and the other had been diving 35 years ex military, commercial and tech diver with a van packed to the hilt (no metal detector though!!!) They marked the heading based on the landmark we swimmers use and followed the bouy chain down. It turned out to be only 25 feet and good vis - not 70 feet! as harbor patrol said. They ran a line to the location where I dropped it (30-40 feet or so from bouy) and began the S&R. Unfortunately they could not get ahold of a metal detector and said that the bottom was suspended silt (about 1 1/2 inches of "soapy, floating silt" They did not find it but were pretty sure that if its anywhere near, a metal detector would pick it up...I dont know the strength of those things, but it would be cool to see if indeed they picked up anything. The bouy has a 550lb block on it and doesnt sway much at all... in fact it was glass when I lost it and glass when we went out. (This is a lake(Washington) btw - but the funny thing is I couldve sworn when I stepped in the last time that there was tidal activity - it seemed "low") Also, dont know what the displacement in 25' would look like with a ring. Anyway, trying to get ahold of a metal detector....