If I can find a spot where there was a fire, or even sparkler wires, that means somebody was there at night. If there are bottle caps, that means they were drinking...if there are "signs" that females were there too, that means jewelry...all this tells me somebody probably went skinny dipping, and when shirts and pants come off, odds are good that big necklaces, coins, keys, went flying too..everything in the sand tells you about who was at the spot, and is important for your success...are there cigarette butts? are they menthols? how many? that determines how long somebody was there and increases the possibility they lost something, bottle caps? what brand? something a girl would most likely drink? diapers? bobby pins? hot wheel cars? wheres the nearest place that a girl would go to relieve herself? Wheres the private spot some young lovers would go? Condom wrappers up in a secluded pocket of the dune grass led me to my first gold ring, slowed me down, and BAM! tiny little foil signal, but it has two diamonds and an opal...
I like the "downstream" water of a beach, wherever the prevailing current is running...seems that the main beach gets swept pretty good by local detectorists, but since its such a big place, you gotta smoke jump to the hot spots...I like quickly sweeping where people park their cars, and head up over the dunes, got several silver ankle bracelets here...
I'm looking at a water machine right now, the Seahunter, to be able to snorkle the deeper water, especially after the crowds show up, let me know what you think of yours... but again, location is paramount, and water slows a fellow down, and saps a persons energy pretty quickly. Good luck, there is a wealth of information in the posts that replied to yours!