Cathy, that sounds like a terrible experience. I am surprise you did not lose the centerboard. You must have had it tethered to the boat. Well done!
I've never seen a sidewinder turtle. I'm thinking of a couple of things here:
1. Does your mast have a piece of styrofoam inside it? I'm going from memory, but I think many of them did back in the day
2. Does your mast have a cap on the end? If the air stays in, and water cannot get in, it should be pretty buoyant.
I have heard of people with other boats spraying expanding insulating foam in each end of the mast to steal it off so water can't get i. I'm not advising that, just passing the info along. I have seen boats with plastic milk jugs tied to the top of the mast (and I have heard it works well, although so much for fashion...), and I've seen boats with Hobie mast floats mounted up there.
I once say a guy who had made a couple of brackets out of aluminum that he slid down the slots for the nylon bushing, on each side, after the centerboard was installed. The brackets looked really good and screwed into the aluminum frame around the centerboard slot. With that setup, the centerboard could not be removed.
Paul
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