Half Moon bay is routinely detected, no problem. Those are all state administered beaches (maybe some city beaches too?) And city & state of CA beaches have just always ever been md'd with no issues here.
Or ... you can go with the technical answer: Since the state park's dept. that administers them ,
is the exact same park's dept that administers the inland parks, then .... technically: The same "cultural heritage issues" would apply. Ie.: you can't find a 50 or more year old coin. So ... naturally you will bring your calculator along, right ?
Or .... surely the states lost & found laws apply. So if you find a ring worth over $100, you will turn it in to the police dept.
And ... surely, the IRS and state income taxes apply. So you will certainly list the income of the clad on your taxes.
And ... surely ... you should check with the proper authorities as to whether "harvest and remove" clauses apply. And/or "alter and deface" (you're going to dig after all).
Or you can be like everyone else here, and just go Half moon bay is routinely detected
One rule you *should* be appraised of is: You have to send Tom_in_CA a 30% cut of all your finds made in CA. After all, it's in print now. And if you doubt this rule, just email me and I'll confirm it. I accept paypal.