I sail a 30 footer. I was knocked down as I approched the marina entrance in about 3 knots of breeze. Out of the south came a gust I was later told topped 60 mph. I was so close to the shore (breakwater) there was no time to prepare. It wasn''t a really big deal I let go the sheets the sails drained, the boat righted hersels and the cockpit drained. I was embarrased but never in any danger. I have been hit by these same sudden gusts while I was in open water. I saw them coming at me across the water and was ready when it arrived..