Detecting with a vlf just gets a bit tricky moving from dry to wet, or in the actual water itself. Most vlf's don't fare too well in the latter areas, and although you can get the ground balance to quieten things down to a usuable state, it will often come with a sizeable drop in depth capability. Don't rely on the ground balance alone, as you will need to have a play around with the sensitivity setting to help reduce falsing - don't be afraid to drop it by a fair bit if necessary. Also remember that the 18.75kHz eliptical gold coil is not waterproof, so don't submerse it in water.
If you want to detect the wet sand, best to run parallel to the beach so you are not constantly transitioning from dry to wet, and back again. Also running with the coil an inch or so off the surface will reduce the amount of falsing.
Whilst I quite enjoy running a vlf on the beach, mainly for the more recently dropped finds, you do have to be careful when heading towards the wet sand, as although it may be dry on the surface, dig down a little and you may find it is quite wet underneath. This is where you start to get those "ghost" signals that disappear upon excavation of the hole, in those circumstances you should start to think about dropping the sensitivity back to reduce falsing, and only dig repeatable tones.
Whilst I prefer my more capable Etrac for wet sand/water detecting, I have probably found more spendables on the beach over time using a vlf, mainly from gridding up the dry sand where people had frequented the area during the day. A vlf is quicker to swing, and you can generally cover more ground to maximise recovery of targets vs the heavier multi-frequency detector which require a slower swing speed. Gridding is the key to finding a good bag full of coins. Pick out a well frequented area and drag your foot or shovel in the sand so you can see where you have already detected, this will ensure that you won't miss any targets vs randomly detecting all over the place. Spend a little time earlier in the day to see where a majority of people gather on the beach, this will give you a good starting point for your gridding.
Make the best of what you have, and I'm sure you will manage to come up with some good finds.
