OP here. I guess this needs a follow-up. I was in a sailing boat with some friends and although there were big waves, the wind wasn't too strong so we thought it would be safe sailing. We were wrong about that. An exceptionally big wave came up from behind. The boat started surfing uncontrollably down from it and eventually flipped. I was caught by a rope and dragged under water. Fortunately I had a safety knife strapped to my leg so I could cut myself free but it took some time and I lost consciousness before I could make it up. My friends dragged up on the upturned hull of our boat because they were unable to flip it back. The tide was rising so the current pushed us close to the shore. In the surf we were trown off again and because of the waves it was too dangerous to approach the boat again so my friends swam to the shore, dragging me behind them. I regained consciousness for a while but passed out again as soon as we made it to the beach. Hope this answers all your questions.