Humphrey,
Precisely what the last post said, steer mostly with your sails.
In a situation like this, you DON'T want the rudders to be held down to the sand.
When the boat gets pushed backwards (and it will), SNAP, there goes things like, rudder, casting, TRANSOM, and any combination. They break easy enough in these conditions anyway. When extreme, I would often leave my rudders locked UP, and use the sails to navigate.
When it's extreme like that, using the technique you propose MAY help., but it's really ALOT of skill, and about the some luck.
Even then though, if you just steer with the sails, you won't have enough power to gain against the onrush of water in the waves. On the N20 anyway, you have to have some board and some rudder to get enough bite to make any significant upwind progress. Sheeting and trimming sails IS definitely important ... like making a big ease on the main as you top a wave to keep you from getting auto-tacked...but you have to sheet and counter-steer to get going in the flat past the wave. The other biggie is to watch the water flow of the wave as it gets to the rudders. Because you get a big rush of water suddenly moving in the opposite direction, your rudders work backwards and you need to be ready to back the boat in the water without switching your heading. It's tricky getting through that stuff but I feel like I learned a lot that day.
