Water vessels of any kind are probably the most susceptible things in the world for mold growth for one simple reason: they spend most of their existence in water.

Mold, also called mildew, is a member of the fungi kingdom. The main thing it requires in order to grow, thrive, reproduce and spread is moisture. It also requires food, but boats provide lots of things for fungi to eat like in carpets, wood, cushions, and the stitching in some vinyl upholstery, among other areas. Any organic or cellulose based surface (wood, upholstery, sheetrock, etc.) that remains damp for more than 24 hours is potential food.

Boats that remain in the water all year around suffer humidity and spray from lakes or oceans. In dry storage they would be safer, but only if every last drop of moisture was removed before they were stored. If there was any level of dampness or the storage air is damp or humid, you may be in for a nasty shock when you go to retrieve your boat. And if it's been covered with a tarp or other covering, it could be even worse because mold loves damp dark places with little or no air circulation.

The best way to avoid a problem is to keep all surfaces that aren't actually in the water as dry as possible. Of course that's a big challenge and you might need some help in the way or moisture absorbers.

If your boat does develop a problem, read How To Remove Boat Mold. Follow all directions and guidelines, as well as EPA guidelines to the letter.

Mold can be harmful to your health and cause quite a bit of damage to your property. Take clean up and remediation seriously, wear proper protection and leave big jobs to the professionals.