If you have a damp interior—as frequently happens in tropical locations or during long runs of humid weather—the bottoms of your boat mattresses may get moist. That’s when mold, mildew and bacteria take hold. Although liveaboards seem to build an unnatural resistance to some pretty pungent environments, I’ve found over the years that even some of my most enthusiastic and eager crewmembers soon become miserable with allergies if the boat is plagued by mildew.
We’ve done plenty of articles on fighting mildew with sprays and dehumidifiers, but it’s better to prevent mildew altogether. Here are three products that can help keep that mystery moisture from appearing under your bunk cushion or mattress. Combine any of these products with a routine treatment of our penny priced homemade mildew preventative “Formula B” and you should not have to worry about bunk mildew smells again.
HyperVent is a 3/4-inch mat of stiff coiled plastic, 39 inches wide, bonded on one side to a breathable fabric. The spun polymer can be cut with scissors, but a template is always a good idea. It permits air circulation under a mattress. It weighs but 4.3 ounces per square yard, can be washed, and will outlast any mattress. It’s not cheap, but it could save your cushion. There’s a similar product aiming at the “van-life” vagabonds called Den-Dry, which we have not tested.
Another option is Dri-Dek, 9/16-inch-thick, foot-square, polyvinyl chloride interlocking tiles coated with something called Oxy- B1 to further inhibit mold, mildew, and bacteria. This product isn’t just for use under mattresses; it is a popular locker liner as well. It can be fitted with a knife, comes in 12 colors, and is sold by the tile.
A couple of other products that we have reviewed behaved like diapers, expanding as they absorbed moisture. One was Dry Bunk, the other was Ventair, but we could not find a source for either of these fabrics – which were sold by the sheet.
For more on choosing boat mattresses, our archive report compares types and materials, and although some new products have entered the market, the overall findings are still valid today. Also, for comprehensive look at keeping mildew and odors at bay throughout the boat, see our two-volume eBook “The Mildew Free Boat.”