It's basically a small Army base adjacent to most of the beach so that's why you can't park there. There's some public parking at the public access area at the south end. If you owned a house that was up against a private beach, I doubt you'd let people park in your driveway or cut through your yard to access it.
> If you owned a house that was up against a private beach, I doubt you'd let people park in your driveway or cut through your yard to access it.
There's a concept in common law called the public trust doctrine[1] that we inherited from our British legal lineage that many states incorporate into their handling of beaches.
For example, some states hold all beaches in public trusts, and everyone has the right to use them. There being no such thing as "private beaches", although riparian rights can be rented, also means that the public has a right to access those beaches even if private property blocks access.
In those cases, the public has both perpendicular and lateral beach access rights, the former meaning you can legally cut across private property to access beaches, the latter meaning that you can walk up and down beaches to access other beaches.
That's to say your feelings about people crossing private property don't really matter when it comes legal beach access, Hawaii holds all waters and beaches in public trusts via public trust doctrine that courts have held up for literally centuries.
States are allowed to interpret public trust doctrine independently and as a result, apply it differently between states.
I'm not aware of any states that have private beaches, but states have different interpretations of, for example, how much dry sand can be accessed by the public if dry sand can be accessed at all.
