I use mine all the time over on the east coast of Florida and will wade out to about knee deep when it's not to rough and slow swing the Coinstrike. Now, if you hit black sand, you will have to drop the sensitivity down to as low as 2, but don't worry, at 2 the Coinstrike is still getting a good 6 inches. Just remember to ground balance again when you go from dry to wet sand. I also run with ground tracking on most of the time so I don't have to GB quite as much. I also hip mount my Coinstrike which makes it light as a feather to swing. I dig mostly everything at the beach so I don't worry about target ID or pinpointing.
By the way, the Coinstrike LOVES bottle caps I reckon because their shaped like coins. Now the Coinstrike IS NOT as sensitive to small targets as the T2 is, like finer necklaces or bracelets, but it will hold it's own with any CZ. The drawback with a T2 at the beach is the feedback & falsing. I have tried two T2's and liked then for land hunting but not for the beach and I didn't like them as much as my Coinstrike or CZ's.
If you want a multi-task machine and are willing to put in the time to learn the machine which for me took a good 40-50 hours before I really became accustomed to it then the Coinstrike would serve you well. It really is a like or dislike machine, some like it and some dislike it.