Removing moisture from the boat is one of the first challenges for a liveaboard boat in the PNW. Every day, breathing, cooking, and rain drenched clothing add moisture vapor to the air, and that’s on top of a base level of high humidity the outside air is at during our rainy weeks. And let’s hope your boat doesn’t have any leaks, because that’ll just add more moisture to the boat as we get week after week of continuous rain.
We’re now 5 months into living aboard, and it’s going great! The moisture really started turning on about 3 weeks ago, when the night time temperatures became quite chilly. When the outside temp drops to 40 F but your cabin temp is 62 F, that warmer moist air hits a cold surface (hull walls, deck underside, metal deck fills and hatch frames) and quickly condensates.
We really want to prevent mold from forming (when we bought our boat we had a lot of mold to clean off the interior hull and hidden storage spaces: Tackling the Mold Monster (May 2015)) – and keeping the humidity reasonable is the key.
A Good Dehumidifier
The #1 tool for a liveaboard is a good hard-working dehumidifier. We had heard recommendations for the Eva-Dry EDV-4000 (no longer available, but the Ivation 19 [Amazon link] is quite similar) from 48 North and other cruisers, so that’s what we tried. And it’s working great! It pulls volumes more water out of the air than our small Eva-Dry EDV-1100 did.