I have an Anderson Bailer, purchased from B&B, installed very close to the center board well on my Spindrift 12. It works great until something like leaves, twigs, or acorns clog it up (typical of any boat drain). I too forgot to make sure it was open, then heavy snow deformed the tarp into a huge pocket, then it melted and I could tell what was happening, but by that time the boat had about a foot of water in it. It did not sit all winter this way as the tarp only failed due to a hole created as I was trying to get the snow and melt out. I did not know the drain was closed. Have I mentioned that I really hate working in icy cold water?