Purist beach detectorists will argue that the best time to find goodies on a beach is after winter storms. While that’s certainly true, any time after a crowd has been through (Mondays following busy weekends or the day after a holiday), can mean a fresh crop of coins and jewelry just waiting to be found by your metal detector. Although some beaches can yield historic artifacts, most finds will likley be of the modern variety.
In all types of beach hunting, the discrimination must be kept very low, eliminating only small iron (bobby pins and nails). Aluminum pull tabs and tin foil should not be discriminated or you will lose some gold and/or platinum rings as well. Some beach hunters operate with zero discrimination and dig everything. Using a sand scoop makes target recovery faster and easier.
If you plan to hunt only in dry sand and in very shallow water, a good coin shooting detector will work well if you keep the discrimination set low. If you wish to go out into deeper water you will need a totally submersible machine. Some machines have a single tone for all targets and some have variable tones for different targets. It’s important to realize that most gold rings will read in the “middle” tones (above iron but below coins).
All metal detectors work well in the dry ocean sand but most single frequency detectors become erratic in the wet salt sand or in the surf. Wet salt makes the ground conductive and the detector sees the sand as a large sheet of metal. In order to operate in those areas with most single frequency instruments, you must decrease the sensitivity of the detector and it may still operate erratically. If you only occasionally visit the ocean and own an instrument that becomes erratic in wet salt sand, you can still operate perfectly in the dry sand area. If you live near the ocean, or get to the ocean frequently, consider investing in a detector that will operate well in all conditions including wet salt sand. Those detectors are generally higher priced than multi-purpose detectors, but they are definitely worth the investment if you frequent the ocean. Good luck and have fun!