Which Dehumidifier for a Boat?

For us, a good marine dehumidifier is an essential part of being commuter cruisers.  We have never returned to the boat to find mold or mildew – and have our JBP DryAir, Model DH-5 stainless steel dehumidifier to thank.  There are several considerations when shopping for a dehumidifier for your boat, these were ours:

1.  Continuous Draining.  Most “home” dehumidifiers drain into a “bucket”, which is a problem if we’re gone for six months.  No one is available to drain the bucket daily.  While the price tag seemed attractive, we couldn’t figure out how to jerry-rig a home model to continuously drain , preferably into our galley sink.  We could also have it drain into the bilge, but if the bilge pump failed we might have a problem.  The galley sink automatically drains overboard without including the bilge pump in the loop.

All Teak Inside?  Don't Turn the Humidity Level Below 60%!

All Teak Inside? Don't Turn the Humidity Level Below 60%!

2.  Electricity.  Energy efficiency is a consideration, but not the primary consideration when choosing a dehumidifier unit for your boat.  Energy efficiency is one of the reasons we choose to have both a room air conditioner and a dehumidifier – the a/c unit consumes MUCH more electricity and therefore would be much more expensive to leave running all the time for six months while we’re gone.  The dehumidifier just sips electricity – someplace online said it consumes as much electricity as a light bulb, but all I know is that our electricity bill is extremely low.

3.  Power Outage.  The most important reason to have a marine dehumidifier is it does not have to be reset after the power blips – which it does several times a day or week in locations such as the Rio Dulce, Guatemala and Bocas Del Toro, Panama.  When the power goes out, obviously the unit shuts off.  But the minute the power comes back ON, our dehumidifier comes right back on – it purrs like a kitty while removing all the excess humidity from the air inside the boat!  Regular dehumidifiers have some type of electronics that means they do NOT turn back on automatically after a power blip.  Several cruisers have attempted to buy our dehumidifier after discovering this nuance of commuter cruising.

All Packed Up and Ready to Leave for Six Months :(

All Packed Up and Ready to Leave for Six Months 🙁

4.  Construction.  A good boat dehumidifier will have a low center of gravity, be relatively lightweight and have no castors to roll around.  Typical home dehumidifiers are tall and narrow and could tip with the motion of a boat, even in a slip.

5.  Stainless Steel.  Humidity and salt air cause everything to rust.  Our stainless dehumidifier just keeps on purring and removing water day in and day out (knock on teak!).  Our condensation tubes are copper.

6.  Carry Handle.  Most dehumidifiers are bulky and even the “lightweight” ones are heavy.  Having a carry handle makes it easier to transfer to storage under the pullman berth each year when we return to the boat and get it out of storage when the season’s over.

7.  Reliability.  Given the fact that our stainless dehumidifier cost almost twice what a household unit would have been, it would be nice if it would last a LONG time!  So far, so good.  This is it’s 10th season and our current caretaker reports it’s still purring right along.

So why spend the money for a dehumifier at all?  Won’t dessicant products such as Damp Rid do the job?  Yes, but they fill up very quickly in such a humid atmosphere and need replaced regularly.  If your caretaker is willing to replace them regularly, you might be able to get by with these products, or even raw charcoal as some advocate — we never were willing to try that approach because charcoal is combustible and we didn’t want to add anything to the boat that might blow up or start a fire.

IMPORTANT Dehumidifier Tip:   All dehumidifiers allow you to set the percent of humidity left in the boat.  We never set ours below 60% because too little humidity can dry out all our solid teak staved paneling and woodwork below.  One year a caretaker set it a bit lower than what we left it as and the lid on our nav desk warped and cracked.    Aaaarrrgggg!!!

JBP Dryair DH-5 Dehumidifier

JBP Dryair DH-5 Dehumidifier

Also, it’s important to think through your ventilation plan while you’re away from the boat.  We have a solar powered fan installed on one of our dorades which sucks air out of the boat and other dorades that allow air in, plus the dehumidifier has a fan to circulate air.  So the inside air is constantly circulating, not stagnant, which is another big factor in keeping mold and mildew out.

Do you have other solutions, or know of a place you can buy a dehumidifier similar to ours?   We bought it so long ago and I cannot find an online source that sells them.  Please leave a comment and let us all know!  THX!  Jan




  1. We have a JBP DryAir dehumidifier & love it. Unfortunately they no longer seem to be made as we discovered when trying to find one for some other cruising friends of ours.

    — Geoff

    • Hi Geoff & Sue! We have the same and it’s a shame they’re not made anymore! We met you in LeCeiba Shipyard … some wine-tasting if I remember correctly, among other times… Cheers! Jan & David

  2. Today, I went to the beachfront with my kids. I found a sea shell and gave it to my 4 year old daughter and said “You can hear the ocean if you put this to your ear.” She placed the shell to her ear and screamed. There was a hermit crab inside and it pinched her ear. She never wants to go back! LoL I know this is completely off topic but I had to tell someone!

  3. John Patterson says:

    We have a like new DH5 that we will be selling at auction to support Hawaii Youth Sailing. If you have a copy of the operating manual that you could reproduce and send me, I’m sure it would help increase the value at auction. You can send it to:
    John Patterson
    Rear Commodore for Sail
    Waikiki Yacht Club
    1599 Ala Moana Blvd
    Honolulu HI 96814
    Thanks for any help you can give us!

    • Hi John! We’d love to help, not sure if we have an operating manual aboard, but we’re not aboard … yet. When is your auction? We won’t be back aboard the boat (being commuter cruisers) until mid-October. Let us know, hopefully we can scan whatever we have & help. Thx! Jan & David

  4. We were unable to find the dehumidifier you talked about as yes, it is not available any more. However we bought a very similar one from Mermaid, which has all the features you mentioned. We just returned to the boat in Puerto Vallarta after 3 weeks away and it had worked perfectly. There was no smell or condensation, humidity or mold. It has only 2 settings ( we left ours at low) and it drains into the galley sink. Thanks so much for the recommendation, we would never have thought of getting one otherwise.

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