The rights to to beach access can also be traced to the Code of Justinian in the 6th century: 1. By the law of nature these things are common to mankind, the a

The rights to to beach access can also be traced to the Code of Justinian in the 6th century: 1. By the law of nature these things are common to mankind, the air, running water, the sea, and consequently the shores of the sea. No one, therefore, is forbidden to approach the seashore, provided that he respects habitationes, monuments, and buildings which are not, like the sea, subject only to the law of nations. 2. All rivers and ports are public; hence the right of fishing in a port, or in rivers, is common to all men. 3. The seashore extends as far as the greatest winter flood runs up. 4. The public use of the banks of a river is part of the law of nations, just as is that of the river itself. All persons, therefore, are as much at liberty to bring their vessels to the bank, to fasten ropes to the trees growing there, and to place any part of their cargo there, as to navigate the river itself But the banks of a river are the property of those whose land they adjoin; and consequently the trees growing on them are also the property of the same persons. 5. The public use of the seashore, too, is part of the law of nations, as is that of the sea itself; and, therefore, any person is at liberty to place on it a cottage, to which he may retreat, or to dry his nets there, and haul them from the sea; for the shores may be said to be the property of no man, but are subject to the same law as the sea itself, and the sand or ground beneath it. TLDR: Really old Roman dude said watery stuff is public.