Join Date: Jun 2000
Location: CT/ Long Island Sound
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Re: How often should I take her out of the water?
As Fallard hints, leaving a boat in the water for long periods MAY promote absorption into the gelcoat and fiberglass layers, leading to high moisture levels in the different strata. This can be a problem if the moisture is present when the temperature drops below freezing. The water expands as it freezes, and blows the layers apart. This results in delamination - a real weakening of the structure wherever it occurs, because things that were supposed to be held together aren't any more. This is less of a problem with solid fiberglass than with boats built with a core (balsa, foam, or whatever) with layers of fiberglass on both sides. You don't say what kind of boat you're dealing with, so moisture absorption may or may not be a big deal.
Leaving a boat in the water for a long time can also cause osmotic blisters. This happens when water seeps into microscopic cracks in the gelcoat, and reacts with the chemicals it finds there. The result is blisters in the gelcoat. This can also affect the structural integrity of the hull if they are big: eventually one or more of them could cause a leak. Osmotic blisters can be fixed by popping them and filling them with an epoxy filler, or in severe cases, by stripping the entire gelcoat and re-applying one, along with an epoxy barrier coat to prevent it from ever happening again.
So..... leaving the boat in the water for a really long time could cause problems. Or it might not. As fallard suggests, you can have the boat hauled and see if any of the problems actually exist. If they don't, no problem. If they do, then you'll know.