when the boat goes fast I get water coming in through the centerboard slot. No problem, except one day when I was going really fast in choppy water it came in faster than went goes out through the two drain holes. " I'm Sinking!" I said to myself. I found getting my (solo) weight forward and flattening the boat helped reduce the incoming H2O and I survived. 1) is this a common problem? 2) what can you do about it?