Going back to yesterday and Daves concern about would this stand up to winter storms. This is only my guess, but on the beach are several thousands of tons of assorted size rocks apparently dropped at random in piles, just as if they were surplus to requirements. No pattern at all. But it has obviously cost a lot of money to transport them to here, so my guess is they will, in the end, be part of the construction jigsaw. Only time (or a construction engineer) will tell.