“Twenty years from now you will be more disappointed by the things that you didn't do than by the ones you did do. So throw off the bowlines. Sail away from the safe harbor. Catch the trade winds in your sails. Explore. Dream. Discover.” – Mark Twain

Winter Liveaboards – Warm & Dry


To continue on the winter liveaboards theme, let’s talk about keeping the boat warm and dry.

When evaluating heating options there are two types of heat to consider: radiant heat and forced air heat. Both have pros and cons.  The radiant heat is typically supplied by oil-filled radiator style heaters.  This can give a long last deep warmth that will transfer heat into everything around it like the wood, fiberglass, cabin cushions, etc.  The down side is they take time to heat up and when you open up the boat you can loose heat that will take a long time to restore.  With forced air heaters you can rapidly heat the air but its not the deep lasting heat you get from the radiant heaters.  When you turn off a forced air heater the heat immediately goes away.

There are many ways to heat a boat.  If we were going to do this long term an Espar diesel heater would be tops on my list of upgrades.  This would provide either a constant radiant or forced air heat depending on which system you choose.  I would likely go for the radiant water heaters.  But these are costly to install and do require significant maintenance.  Since we are looking at a shorter term view this left electric and propane as the viable heating options for Smitty.

In talking to other liveaboards here as Constitution Marina, propane seems to be a primary choice.  There is even a retired guy on one of the boats that makes some extra money by making propane runs for people.  The Mr. Buddy Heater seems to be a popular choice around the marina.  We had a Big Buddy Heater that we used for tailgating at football games and heating the garage.  These are forced air heaters that are great at creating a quick warmth. These heaters have great built in safety features like low oxygen sensors and tip-over safety mechanisms.  Officially they are not safe for indoor use in Massachusetts but they are in the rest of the country.  Go figure.

big buddy heater 2The heater would take the chill out of the garage.  For the boat it could be a little overkill with the two heating elements compared to the single element of the Mr. Buddy.  These heaters can run on the small, one-pound green propane canisters but that will only last about 5 hours.  The best way to run these heaters off of 20 pound tanks with a hose and filter.  This setup will last 3-4 days.  Two tanks could get you through a week.  We could use this for the primary heat source but we absolutely would not leave this unattended.  My Bride is even leary of using this on her own.  But it’s important to have a heat source that doesn’t depend on electricity as our friends Tom and Nancy at Tidal Life learned during the blizzard of 2012.  We ended up bring this heater to them when they lost power.

Electric is another option.  There are quality electric oil-filled radiator style heaters.  Some are fancy with built in thermostats, timers, etc.  But these can be problematic when you lose power.  They won’t reset.  So you are better off going more low tech.  Since this would be the heater that is typically left on when you leave the boat, some safety features to consider would be UL rated for safe use around water, tip-over safety and overheat protection. Through the Boston Liveaboard Yahoo Group, the DeLonghi TRN0812T oil-filled radiator heater was recommend.  Its compact and includes the safety features you would want on the heater.

electric heater oil filled

It was also relatively inexpensive at $72.  The compact size is nice on the boat and its safe around Summer as the outer portion of the heater is relatively cool to the touch.  Size wise it doesn’t make sense to go over 1500 watts for a boat.  The electrical sizing in one of the largest issues to get past on most boats, see below for more discussion on this. This heater draws up to 1200 watts on high but has medium and low settings that will draw 700 watts and 500 watts, respectively.  The total amperage for this heater is about 12 amps.

We also have a small forced air heater.  Prior to being full-time liveaboards we used our boat for an extended season from April to December.  During the early and late parts of the season we used this heater to keep the cabin toasty at night.  This heater does a great job for spot heating.  It’s not UL safety rated for use near water but does have tip-over safety.  I wouldn’t leave this heater on unattended.  This heater uses either 750 watts on low or 1500 watts on high. The total amperage for this heater is about 13 amps.

Depending on your boat you may also have a section that needs minimal heat to keep things for freezing. On our Catalina 310 there is a section under the cockpit that houses the water heater, plumbing for the stern shower and the holding tank.  You can access this space from either the rear berth or the cockpit.  On Andrew’s C310 he puts a heat lamp in this area set on a timer.  A couple of years ago we purchased a Caframo marine forced air heater.  This heater has an anti-freeze setting.  We setup this heater on the anti-freeze setting in that rear area.  This heater has 3 settings and uses 600 watts on low, 900 watts on medium and 1500 watts on high.  The anti-freeze setting can be used on the 600 watt or 900 watt settings.  We set this on medium and that uses about 7.5 amps.

The dry in the title isn’t just referring to my Bride’s motto of “warm and dry”.  When you heat the air in the boat a side effect is condensation.  This can be a bigger problem then staying warm.  To combat this most liveaboards will run some kind of dehumidifier.  Andrew has a larger 50-pint/25-liter unit.  These run 24/7 and will remove a lot of water from the air.  We went with a smaller 25-pint/12.5-liter unit that is more compact.   We have to empty it daily.  As a plus it really helps move air and reduce the heat stratification, see below. This unit uses about 190 watts at 1.6 amps.

heat stratified

Image from here.


Heat stratification is a significant problem on boats in the winter as well.  It is possible for your head to be sweating while your feet are freezing cold.  The dehumidifier helps some.  But the best answer is fans.


Image from here.


Some of our 12-volts fans run non-stop to keep the air moving around the boat.  This helps and make the air temperature more uniform.  This will also help with the moisture issue.

So who’s paying attention? How much power did I just say we are using to keep our boat warm and dry? A total of 3,790 watts/ 34.1 amps.  Through a 30 amp shore power connection.  And this doesn’t include the battery charger, water heater or anything else plugged into the 120-volt outlets on the boat.  The biggest limitation on electric is the 30-amp shore power connection.  Some liveaboards will add a second 30 amp shore power connection wired to a couple of outlets.  Others will simply run an extension cord from the shore power pedestal to a heater.  The problem with that is its not really safe to run heaters on extension cords as they can heat up and cause fires.

So I made a temporary electrical panel to use during the winter.  Using a small breaker box I salvaged from a construction site, I wired up this panel.



The panel consists of two 20-amp breakers wired directly to a shore power cord.  I cut the boat side end of the shore power cord, stripped back the insulation and wired it to the breakers inside the panel.  Then each breaker is wired directly to a single outlet.  We ran the cord for the temporary panel in from the rear berth hatch that is in the cockpit.  We sealed and insulated the window.  Plus its under the shrink wrap so there are no issues with water getting in right now.

This gives the additional electricity needed to keep our boat warm and dry.  We run the forced air heater on high on one of these outlets when on board and as needed.  The other outlet is used for the dehumidifier and the Caframo heater setup in the back area.  Yes, I did run an extension cord to that heater.  But we went with a 10-gauge wire, 15-foot cord.  Since this heater does not run often and not for extended periods of time I feel safe with this setup.

On a typical day we will run the oil-filled radiator heater on medium or low all the time.  This keeps the boat around 58-65 degrees depending on the outside temperature.  We can run this heater and the battery charger non-stop. We can also use the water heater, microwave or electric tea kettle without setting off any of the breakers.

The electric only system has been working well so far.  We typically return to a boat that is around 58-60 degrees.  Within minutes it will be up to mid 70s with the forced air heater running.  We will then typically turn down the heaters.  We try to keep it between 68-72 while we are awake and around 58-62 while sleeping.  On the extreme side, we have had it over 85 while it was around 20 outside.  This system is not the cheapest on an annual basis but for a one year plan its ok.  Based on what we have been told by some of the liveaboards at the marina, we are expecting to pay around $300-400 per month on the coldest months.


4 thoughts on “Winter Liveaboards – Warm & Dry

  1. Nice setup. But that is a lot of electricity.
    I was wondering your take on a wood stove (http://www.marinestove.com/index.htm). Of course you wouldn’t leave it unattended. Plus you’d return to a frozen boat after missing awhile, so ac is still necessary. But my understanding is that they radiant well (you;ll need fans to circulate) and suck out a lot of humidity. Plus they are cozy as hell! (no pun intended)

    • Welcome to the land of the free, or maybe not so free. Solid fuel heaters are against Boston regulations, according to our marina. Gotta love it. Cradle of liberty but don’t try to use wood as a heat source. Ugh. 10 more months!

  2. It’s a difficult and often expensive issue to address. We have live-aboard friends here in Deale who heat with a diesel Espar (I think). Forced air. The installation was pricey, and of course, the fuel doesn’t cost nothing. But it’s so warm and effective. Their heating cost last winter (a very cold winter here in Maryland) was significant. But so was ours. . . We heat our house with oil, and used a lot of fuel last winter, just like they did. Just no way around it.

    I have to say, no matter how safe we think they are, the little portable propane heaters are scary. If you use them, be so very careful.

  3. Oh, and great job on the temporary panel! That was a smart idea.

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