C&R, it is not that the Mark II is a poor unit, but a poor fresh water choice. I have used the Mark II, with success in salt and fresh water, but don't count much on any discrimination, if you wanna still find gold. The unit is ALL METAL, period. It is a PI. Discrimination of some sort is good to have in fresh water, as there is very little degradation of metallic targets, as opposed to salt water. Set the unit up, Volume/Threshold barely audible, Standard Trash Elimination and Discrimination/Elimination at 0. Dig it all, but perhaps after some time, you MAY be able to tell the double beeps of the nails you will be finding and leave those in the ground. Be careful though, because earring, chains and broken rings can also double beep some. I pretty much dug it all, at least in salt water, for 2 years and looked like Pop-Eye, LOL! I used thes units exclusively, for my 1st 2 seasons of water hunting, '04-'05. Great unit.