I only ever really let the tides influence my decision to go metal detecting during times of rough surf, otherwise I go to the beach treasure hunting regardless.
Shallow water hunting at high tide in rough surf can be a lesson in frustration, it can also be dangerous depending on how rough the surf is.
I still never wait until two hours before low tide, as way too many beach and shallow water hunters use that outdated method of timing.
Going shallow water hunting just an hour or two after high tide can make a big difference at heavily hunted beaches, putting the first drop off in the water within comfortable metal detecting range.
You will have less chance of getting your scoop or metal detector yanked out of your hands in rough surf, when metal detecting in the first drop off an hour or two after high tide.
It is always nice to be the first one at a promising site, but what is the point if you cannot recover any targets because of the crashing surf.
Fighting to sweep your search coil, pinpoint , scoop and recover is very tiring on the high tide.
You may be ready to leave the beach exhausted just when conditions in the area close to shore start to improve.
Rough surf hunting is a little like weekend hunting, you have to be patient and wait for the best time to go metal detecting.
Go shallow water hunting in rough surf too soon and you risk going home empty handed.