Hi Mary...

At the beach, I usually tie my (heavy) H16 on one side to the wooden stairs (of the boardwalk/deck) from our cottage. On the other side I usually pound in a 3 foot, 2X2" treated wood garden stake (top angled away from boat) into the sand to tie it down. The waves rarely get up to the stair area except during serious storms.
If a moderate to severe storm is coming, I'll take off the mast, flip the boat over, and pile lots of sand on the underside of the tramp, then tie it as above.
Anything more serious and I'll trailer the boat off the beach and tie it to the pylons under the cottage. If we then had to evacuate the island, I'd probably leave it there and hope for the best..

Mark Owens
1976 H16 sail# 19857