I am a NJ beach hunter. You need a multi frequency machine. If you plan to hunt in the water the Minelab Excaliber is the most used machine on Jersey beaches. It will also hunt dry sand and wet sand. If you are planning to go dry sand and wet sand only, the Minelab Sovereign GT is the best way to go. The GT can get it's coil wet but not it's power box. The GT is generally regarded as the best all around beach machine. It is better balanced than the excal and is usable right out of the box. The excal needs an aftermarket shaft to improve its balance. The GT is also an excellent dirt hunting machine. Don't let the fact that it lacks a meter or screen throw you. It's all about beep and dig!
Minelab just discontinued the Gt but It still may be in stock. In addition to Demarco, I recco Gold Digger metal detector Sales in Rariton NJ. The owner there, Ronnie DeGhetto, can set you up with everything you need to attack the beach. detector, headphones and scoop
http://golddiggermetaldetectors.com/ 908- 595- 9933.
There are other machines that can be used at the beach. if you want to spend $2400 there is the brand new MinelabCTX3030. It's gotten great reviews, but may be not the best way for a beginner to go. If it turns out you don't like beach hunting, that's an expensive dust collector!
There are other great machines, however they aren't front line beach hunting machines. Those would be Minelab's Etrac and Explorer. The Etrac does well in wet and dry sand but isn't waterproof. The Explorer also does OK. Both of those machines are more dirt hunters.
There is nothing in Garrett's or White's line up that we would use on our beaches. Some like the Garrett AT Pro. Good machine but not really the best on our beaches.
Fisher has the CZ 21, like the EXcaliber it's a machine that is used in the water. There are a couple of guys using these. But they are primarily using them to dive with.
Lastly, there are PI machines. PI stands for Pulse Induction. These machines find treasure like nobody's business!!! Unfortunately there is no way to tune out the trash and Iron. Which makes them very difficult to use on Jersey's beaches. Generally speaking we don't use PI machines on Jersey's beaches. The time and energy wasted digging junk targets gets old fast and limits your ability to find the good stuff. You've got only so much time and energy. In other areas of the country PI machines excel.