Sofia, each beach in the world "acclimates" to its own norms. So for example, if, as you say, hurricane force waves have battered this beach routinely, as part of the "normal" expected storm season, then the sand probably routinely "comes and goes" to very deep depths. Ie.: scoured out in the storms, and builds back up in the calm seasons. Thus it's possible that when you go out there, after one of the "normal" storms (as severe as it may look), yet it's not really getting down to old sand, because it's nothing "out of the norm".
For example: I know of beaches near me, that face active open un-protected "windows" to the open ocean, that can routinely get 10 to 15 ft. seas. So these beaches are continually "battered" more-so than other calmer (more protected angles) beaches. And as such, we've seen 5 or 10 ft. of sand dissapear overnight at this beach, with nothing but freshly lost (a single season) pulltabs and bottle caps to show for it. Contrast to some other beaches I can think of, where a mere 4 or 5 ft. seas will pull off a mere 2 ft. of sand, and we're already down to the silver coins. So you see, each beach acclimates to its norms. Therefore, you'd have to know what is above norms (more severe) to determine if it's going to go deeper. Also direction and tides play a lot into it. That is: some hurricanes spin waves a certain compass direction, and the next hurricane may approach from a slightly different angle. You need to be familiar with your particular beach, and studying it's angle/face to the open ocean, and comparing to the past history (you can get buoy histories on line, for years/decades past), to know.
Another factor: I have seen, and heard of, some beaches that got SSSOOO wallopped by some past big event, that scoured out SEEEOOO deep, that literally, no one has ever found an old coin since then! It's as if the sand got dragged out by some storm in the 1970s or '80s, and when the sand finally came back in during the following calms, metal targets did not come back in with the sand. Only the sand itself. So at a beach like that, we only find losses *since* that time. An exception would be if a newer storm goes further back *in* to the dunes (as opposed to merely *down* on/in the wet sand parallels)
