When a CBI sailor capsizes his or her boat, our staff plucks them out of the water and returns them to CBI safe and sound. While we retrieve their vessel they have an opportunity to find something dry to put on and fill out a "Capsize Report". One of the questions we ask on the report is something along the lines of "What caused you to capsize? What happened?". From time to time folks have reminded me that if they could answer that question then they probably wouldn't have gone swimming. So I'm here tell you what may have (most likely) happened. You were not watching the wind. You didn't see the big gust of wind charging along in your direction. You were caught unawares and the wind blew you over. Simple. So all you have to do is watch the wind to anticipate when it will hit your sails and be prepared to to ease them out, and more importantly hike out hard and allow your boat to head up (some) as your boat heels over in the gust..
But wait, you may ask. I can't see the wind. Air is clear. How can you possibly see it and therefore anticipate when it will strike the sails? Ah Grasshopper, here you ask about one of the great secrets usually revealed only to those already in possession of the secret handshake. While I am not willing to reveal anything about the handshake I am willing to reveal the secret of "seeing the wind"
You can't see the wind. You can see the surface of the water which the wind rubs against creating little wavelets or wrinkles as it moves along. The more wind the bigger the wrinkles you can see on the water. On gusty days if you just sit and watch the water sheet for a while you will see big dark areas on the water surface moving along quickly. Kind of like moving ink blots. These are gusts. Wind does not simply move horizontally. A good bit of it moves up and down. When a significant downdraft hits the water surface, it spreads out and moves in the general direction of the prevailing breeze. There can be a significant temporary change in the direction of the gust. If you are caught (surprised) by the leading edge of the gust which probably changes direction by 10, 20 30, 40 degrees or more (on the Charles River), then you have a good chance of a surprise tack or jibe. This can leave you sitting on the leeward side of the cockpit while the boat heels over and fills up with water. You probably won't recover from this before finding yourself completely immersed in the water and wondering just what happened and why.
To avoid this adventure in swimming, pay attention to where the wind is coming from all the time. Keep looking upwind at the surface of the water for dark areas that are moving in your direction. As a novice sailor you are most interested in managing the sudden increase in velocity. When you become more expert you will actually seek out these dark areas for the excitement and speed they can produce. Sailboat racers are always trying to "connect the puffs" - that is sail to and in the puffs as much as possible.
Happy Memorial Day Weekend!