This proposal has been kicked around before. A bill to grant the public at large the right of passage below high water was pending before the Legislature about 25 years ago. Before it could be enacted, someone took it up to the Supreme Judicial Court for an advisory opinion. The SJC ruled that granting such a right would be tantamount to a "taking" of private property for public purposes, and would require compensation to the landowner.
Of course, since then, the make-up of the SJC has changed quite a bit
