I dive and have used a few different detectors and have settled on the Excalibur 1000. The 1000 only means the coil size as he 800 has the smaller coil.
What makes the Excal my choice is ease of use and depth. With it's Iron Mask feature the Excal can respond to a gold ring under or very near a piece of iron like a nail for example unlike other detectors that disc out the nail and the gold ring too. You don't have to Ground Balance the Excal and it isn't a preset like many others that call it "Automatic Ground Balance."
There are Pulse detectors for underwater too, but many of these also love iron. I've dug many a deep holes for a bobby pin and maybe that is where my nick name came from. But Pulse units are deeper and more stable around heavy concentrations of salt and black sand together. With their deep depth they can reach those targets that are covered by all that moving sand.
The Fisher 1280 is a nice easy to operated water detector, but can be unstable in salt water. The Fisher CZ-20 and newer 21 have two frequencies, have to Ground Balance and have three tone to id the target.
Do your homework and visit the major manufactures sites, read the posts here to make your choice and have at it.
