Goodmore is correct, best detector for the salt water beaches is the Minelab Sovereign if your not going in the water more then mid calf (it is NOT waterproof)............. I see them for $300-$400 used, especially the earlier models...Sov GT used will be a little higher......
It will null on iron, (momentarily loss of threshold) telling you the target is iron, It will also null then give you a signal if there is a good target next to the iron.....I can put a iron nail through a gold ring, sweep over it with my Sovereign GT and it will null, then tell me the gold is there...............Others will just see the iron. There is a lot of tiny pieces of iron on most salt water beaches....
I also have 6 detectors, 2 Excals I have modded with special coils, a waterproof Sov GT that can go in the surf and a non waterproof Sovereign GT, a Fisher 1225X and a Whites 6000 XL Pro.....The Sov has BBS, 17 frequencies from 1.5 kHz to 25.5 kHz that it transmits when your detecting, I also use to own a Whites Beachhunter ID..........the Beachhunter has 2 freqs. Not putting the Beachhunter ID down, but if you can get a Sovereign I would highly recommend it, but again it is NOT waterproof.....You can not beat the Sovereign GT for for dry sand, wet sand and very shallow water........I will always own at least 1 Sovereign GT............
BBS is Minelab’s patented multiple frequency metal detection technology. BBS transmits a broad range of 17 frequencies from 1.5 kHz to 25.5 kHz. This broad range of frequencies gives the detector more information about a target and the surrounding environment. BBS technology can be found in Minelab’s Excalibur, Excalibur II and Sovereign metal detectors.