July 10, 2006 - Unusual Solution to the Soggy Mattress Syndrome
by Michel & Jane DeRidder

Once upon a time on Magic Dragon we had soggy undersides to our bunk mattress, an all-too-common problem on cruising yachts venturing into colder latitudes - unless the builder had the foresight to make the mattress base of slats. We frequently had to prop our mattress up to air and dry. We had not only used plywood, but horror of horrors - we had painted the bunk plywood base - a NO-NO. Painted surfaces invite condensation from warm bodies. We have frequently been on cruising yachts with mattresses propped up to dry, so we know we were not alone. Michel finally devised a solution, but not until several years and mattresses had elapsed.

Bunk slats.

He screwed 3/8 by 1-1/2-inch unpainted wooden slats onto the plywood an inch and a half apart to keep the upholstered foam mattress from touching the painted surface. Then for ventilation he drilled 1-inch holes, regularly spaced along the outer edge of the bunk. Finally, to encourage a free flow of air underneath the mattress he made "chimneys" of 1-1/2-inch plastic pipe, four of them against the hull. The painted ply under the 8-inch foam mattress may still get damp on cold nights (we like to sleep with the hatch over the bunk open) but the firm mattress being elevated does not. The system has worked well to eliminate the soggy mattress syndrome. Why didn't we think of this simple solution twenty years sooner?

Under-mattress chimneys.