Hi ikon, I have the GT (10" coil),an Excal 1000, and a Quattro (10.5 coil)and use all of them at the beach. I've found that the GT works best in the Disc. mode (minimum disc. with iron mask on)with sensitivity in the maximum manual without falsing (about the 11 o'clock position here in Daytona Beach),while the Excal is best in the Pinpoint (all metal) mode. I'm still learning the Quattro. Yes, I take the GT into ankle deep water (I chest mount it & wrap it in plastic) and am quite happy with the results. Just remember to swing low & slow. Last Monday at Daytona Beach I was using the GT and was in the surf line and got the tiniest rise in the threshold. I switched over to all metal/pinpoint and didn't get any signal, so I new that the target was deep. Digging down an honest 14 inches I got a very small sheet metal screw that was no bigger than 1/8 inch. True, it was not a good target but I wanted to see just how the GT stacked up against my Excalibur and Quattro. For the money, the GT is darned hard to beat.
Hope this helps & Happy Hunting,
Stirling, N5PIP
Daytona Beach