I spent about 20 minutes getting my Nacra 6.0 up from turtle (twice - dang mainsheet was cleated during righting) this past weekend when an informal race fleet got nailed with a 40 mph blast from an incoming storm. The three boats that capsized went turtle because we were all on beam reaches and the ensuing capsizes placed the masts downwind of the hulls in the water. After seeing the forces involved with the wind pushing on the boat in this attitude, I don't think that there is much that will prevent every turtle. However, something like this might slow down the inversion and speed up the righting process - perhaps even make it automatic. I'm happy to say that my mast was sealed quite well and we got the boat up from turtle in a matter of minutes. The other two boats weren't as lucky as both had water in their masts and had to get powered assistance to get back from turtle. SEAL THOSE MASTS!