Moisture Control on a Boat

Living on a boat means moisture. Water is above and below. The boat is literally suspended in water and floating on a river. And of course, to be suspended in a river, rain is necessary to keep the river a river. And when it rains there are fittings, screws, bolts, instruments, portlights, windows, hatches, and other hardware protruding through the boat where the water can find its way inside.

Water doesn’t even need to come from rain or a river. Water is in the wind. Water is in the air we exhale. Water is in the pots we boil. Water condensates when there’s a warm side and a cool side of the hull or deck. So regardless if the water source is an annoying drip from a leaky deck fitting or condensation after boiling water for noodles, living on a boat means moisture.

We will never be able to stop the moisture, but we can take steps to help control it. And with this video we share our top 10 tips for helping control moisture:

Tip 1: Throw Carpets

Add throw carpets to the cabin sole. Walking down the companionway into the boat with wet shoes and a dripping coat after coming in from the rain and landing on a carpet is a great way to keep moisture in check.

Bonus pro-tip: make sure the carpet has a built-in rubber backing. The rubber backing does two things, first, it is non-slip (the boat is in constant motion, even at the dock), and second, it creates a second moisture barrier between the pile of the carpet and the cabin sole.

Tip 2: Shoe Tray

After landing on the carpet, remove those wet shoes and place them on a plastic shoe tray. The tray will collect water & debris and keep wet shoe soles off the cabin sole. 

Tip 3: Hang Coats

True Oregonians are shunned if using an umbrella. A waterproof jacket with a built-in hood is the way to go. Besides, we don’t have space in the boat for an umbrella to properly dry. Therefore, get a good jacket and hang it in a space where it can dry. Preferably in front of a fan.

Tip 4: Fans

If the air is moving, there’s less opportunity for the moisture in the air to stagnant and collect on surfaces to form condensation. And hanging a coat in front of a fan helps the coat dry out.

And although we didn’t purchase the Hella Turbo Fan, they’ve been on the boat chugging away for many years. They also appear to be user serviceable. 

Tip 5: Froli Mattress System

This mattress system has been a wonderful addition. It lifts the mattress off the surface of the bunk which allows for air circulation underneath the mattress. And it gives an additional layer of comfort than only having the mattress directly on the bunk.

Tip 6: Insulation

A quick and easy way to add insulation is to look for closed cell foam gym floor mat tiles. We installed these along the sides of the v berth bunk and it has provided three main benefits: 1) it creates a barrier between our warm mattress and the cool hull which helps reduce condensation, 2) it adds extra padding for when one of us is tossing & turning in our small bed, and 3) it helps keep the warmth in.

Tip 7: Moisture Collectors

DampRid is the brand name we’re most familiar with. But essentially these silent little powerhouses do their job via crystals. Magic crystals? Maybe. But these crystals collect moisture in the air in a reservoir or pouch. Stuff them in closets, under bunks, in drawers, in hanging lockers, or other places where air doesn’t circulate as much.

Tip 8: Dehumidifier

These come in many shapes and sizes but the one we use while at the dock & connected to shore power is a household size beast. It cuts through the moisture and we consistently see humidity levels in the cabin below 50%, even during the wettest of days (currently as of writing this article we’re at 46%). 

Tip 9: Tarps

You don’t have to deal with a leaky hatch if the rain never reaches the hatch itself. Tightly secure waterproof tarps over the cabin top of the boat to keep the rain from even falling on the boat. Sure, we don’t have 100% coverage, but any extra barrier helps. 

Bonus pro-tip: measure the area where a tarp can go and use the single biggest continuous tarp as will fit. This way you don’t need to deal with seams or overlaps.

Double bonus pro-tip: keep the tarp taught! Bungee cords work well for this.

Triple bonus pro-tip: tarps won’t last forever. Mentally and fiscally plan on replacing it more often than you’d like. 

Tip 10: Butyl Tape

Fiberglass, epoxy, and marine-grand sealants are needed to properly bed deck fittings, portlights, and hatches. But in the darkest depths of a cold, wet, winter it is not realistic to properly make repairs. During the winter the temperatures and humidity levels are not often in agreement with the manufacturer's material specs. Therefore, we need quick fixes to prevent leaks. Enter our dirty little secret: butyl tape. It’s malleable, can be easily applied, and is cheap. A nicely applied strip of butyl tape around the edges of a leaking fitting is often all that is needed to keep it dry until summer when a proper repair can be made.

Video Link: https://youtu.be/WoAiDVb5cTA

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