Here is a trick I learned from A-Class sailors. Secure the mast so it won't rotate. Tie a long line to a trapeze wire. Take the line well out from the side of the boat and tie it to something secure (tree, post, fence, ground anchor). Do the same thing with another trapeze wire/line extension on the other side of the boat. The boat won't go anywhere.

We did that with the Taipan 5.7 in our yard to secure it for Hurricane Wilma, which had gusts in the 100-mph range. The boat hopped up and down a bit on its cushions, but probably only due to the lines not being tight enough.

This probably is not a good option as a permanent storage solution, though, as somebody could walk past the boat and not see the taut wire and behead himself. (I suppose you could put ribbons on the wire to warn people it is there.)

Now, I don't understand WHY this works, except that it has something do with a fulcrum. But I'm sure that all you engineers out there understand the principle.

P.S.
I'm not sure, but I think that after one boat is anchored down in this way, that boat can, in turn, become the anchor point for a boat on each side of it -- like if you have a row of boats close together and need to get them all anchored down quickly.