I just received mine and took it out yesterday after work. I went to a beach here (Lake Michigan) well known for iron trash (actually, all trash). Really, if people knew how much rusty iron sharpness there is they wouldn't jump around in the water there much less let their kids play in it. Its everywhere! I have an AT Pro and its fine in the water, once you get 2 or 3 ft in, but right along the wave crash it always gets a bit squirrely. I really wanted to see what I could find there. In an hour I dug 50 chunks of iron (nails, screws, sharp whatsits that look like shivs, bolts, ect ect) and 1 penny. This iron is all very old with huge concretions. However even with the disc set to max these iron chunks still sounded off (but it would ignore the ptabs I could see on the surface). I learned a lot about whats going on in the water at this particular beach. I was impressed actually believe it or not! It never falsed, if I got a hit I could find it pretty easily and noticed quickly I could get a feel for the size and depth of the target by the volume and the shape of the sound. If the threshold was much past 3 there was a lot of background noise...it could be this beach is just crazy, but what can you guys normally run it at? I wish I could have gone in deeper water, but the water was way too cold yesterday, even colder than a week ago when it was too cold. I'm confident this is going to work for me at cleaner beaches and in the salt when I'm on vacation. Looking forward to spending more time with it!