Dec 2, 2020

Winter Liveaboard Safety and Comfort

Eugene Day - December 2020

I am not a marine professional, or an electrician, or any of several useful things. This is more or less an off the cuff review based on my experience of living here on several boats through 24 winters, and from the experience of my neighbors, and some reading.

I would be happy to answer any questions through the GPSA mail list or privately.


The primary risk in winter is slipping while getting on or off a boat and hurting oneself, ending up in the water, or both. This has happened to several people I know. Long term health issues as well as death have been the result of falling in the water here in the marina. Take the water seriously in the winter.

Ladders are dangerous all year round, they are more dangerous when carrying things on and off boats when hands are not free to use handholds, and even more dangerous when covered with layers of ice and snow. Try to avoid combining the acts of getting yourself on board and bringing things onboard if at all possible. Place objects on the boat, get on, then move the objects onward. Better yet, hand them up to someone else.

If one gets in the water, there are a series of physiological stages, initial shock by contact with cold water which lasts for a minute and can cause immediate water intake and drowning, recovery but with gradual loss of coordination and strength over tens of minutes, and the onset of hypothermia in about half an hour. Practically, one has five to twenty minutes to get help or get over to a location where one can get out on one's own such as by a swim platform or ladder. One can survive longer immersion if secured but are no longer able to help oneself.

I recommend carrying a whistle on a lanyard, perhaps along with the gate key. If you have a voice to yell, fine, but whistles carry and people will react if they hear them - Use both.

Remember that boats are fairly well insulated acoustically, it is not easy for people to hear you especially if TV, fans, or other internal sounds are present. If you have a cell phone still at hand, you can consider calling someone you know is available, or the dock security number. Helps to have a cell phone in a water-resistant case with a lanyard.

Getting help is ideal, although even then getting a large adult in winter clothing out of the water onto a dock is a challenge, requiring several people, lines, and quick and correct action. In many cases, it is better to secure a person in the water with a line, and then bring them over to the ladder or platform for extraction. Given enough help, lifting a person or animal out directly to the dock also works. But know where your closest escape options are, platforms and dock or boat ladders. Think about how you would get to them, and what you would do to get out of the water once there. Climbing onto a swim platform is not easy when fully dressed. If your boat has a swim platform ladder, fold it down into the water to be available to yourself or someone else.

Although making the transition between dock and boat is most likely the location for slips and falls, there are other opportunities, including the party barge, entrance ramp, and anywhere along the docks themselves. There will be ice on the docks, possibly with sand, or without. Wear appropriate shoes, and remain aware of the risk of falling in the water. Getting a broken wrist or a hard face plant on concrete is not a way to improve your boating experience. And of course, alcohol causes dilemmas in the warm times, it is far worse in the cold. I recommend escorting people to their boats, and more generally, in the winter weather, plan to walk with someone or let someone know that you are out if conditions on the docks are bad.


The greatest risk is fire, at dock electrical connections, or onboard at the boat end of shore power cable, or within the boat. Continuous high amperage draw just below the breaker thresholds is more than the 30 amp nominal rating cable connectors can handle, they more or less work at 24 amps continuous, and even then only if maintained. The same is true for wall receptacles running at a nominal capacity of 15 amps. Eventually, they corrode, become more resistive, corrode faster, and they will fail with or without fire.

Make sure to use waterproofing barrel components wherever available, tightening them securely to make a waterproof seal between plug and socket. The connectors do not form reliable connections with the plug-socket connection only, the threaded barrel shell provides necessary mechanical support and waterproofing. Apply some Vaseline at the point where the cable enters the connector cover to discourage water from seeping in. This is not an issue on molded assemblies but a problem area if connectors have been replaced. Performing inspection at the beginning of winter season, at a time when HVAC no longer provides heat, at some point during maximum consumption period and at end of the season is only slightly overkill.

Getting and distributing adequate electric power in winter especially after the reverse cycle AC system no longer provides heat (when the water temperature drops below 40 F.) is a challenge. Boats fall back to pure resistance heating through built-in or portable heaters. Few boats are designed to be used in winter, and this is when it becomes painfully obvious. One needs to have an idea of circuit capacities and loads and how they are balanced across the typical 2x24 amp or perhaps 4x24 amp available shore power circuits. All power may be available for heat, or possibly only half depending on the boat is wired, (my HVAC is all on one 24 amp circuit, the rest of the boat is on the other). This generally entails turning some loads off so that others can be used. One juggles heaters against the stove, water heater, engine compartment heater, battery charger, microwave, washing machine/dryer. The water heater is sneaky since may not come on for a while, but draws 12 amps when it does. I run the water heater to bring the water temp up for the shower, and then turn it off when I cook breakfast. I close off my bedroom with an electric radiator running at 600 watts and am quite comfortable, and then shift heat to the salon when I am up and about.

An oil radiator at 1500 watts is taking roughly 12 amps and should be the only load on the circuit, except for perhaps a lamp or minor electronic device. I try to never run mine at maximum output, keeping them at 600 or 900 watts which gives me a little more flexibility in balancing loads and avoids frying plugs and receptacles. I also use my oven as a heater, with a door ajar. Mine is designed to do this with a sliding panel that props the door open. This is one of the few exceptions to the rule about not using high-temperature radiant heaters. In confined spaces on boats with lots of exposed plastic, wood, or fabric, radiant heaters (ones that glow red) are not safe. Electric radiators do not put out a nice glow, but do put out just as much heat. Portable fuel-burning heaters are not safe either, for several reasons.

Related to problems for creating heat are problems when the heat is not distributed well. Bathroom plumbing can freeze if people and access doors are closed, and putting in a dedicated heater just further complicates power management. I open all doors and storage areas containing plumbing and may use a fan to circulate air. I may put a heater set to a minimum temperature but still must remember that when it comes on it will draw 5 amps at a 600-watt setting, upsetting my lovely balance. Even for boats whose engines are winterized the water system tanks, pump (s), and lines all need to be kept above freezing, even when the wind is howling and it is zero degrees, which does happen here. On my boat, all systems are in the engine compartment, and I keep a heater there which maintains space above 40 degrees F, using I think 200 watts, a couple of amps. 

Winterization considerations. (Boat systems and insulation)

Winterization is generally intended for boats that are laid up for the season and unoccupied. The engine raw water plumbing is filled with antifreeze. The freshwater system is similarly drained, and blown dry, or refilled with antifreeze including all hot and cold water lines. The water heater is drained. Main tank(s) are not filled but are drained with a modest amount of antifreeze added to dilute remnant water and flush lines running from the tank. HVAC systems raw water lines and heat exchangers are drained and refilled with antifreeze. The engine recirculating cooling loop is refreshed with antifreeze to ensure the engine itself does not freeze, typically a terminal experience for the engine and maybe the boater's interest in boating.

This does not work for liveaboards, so systems must be protected in other ways. Several boaters still winterize propulsion systems, especially if the engine spaces are not readily heated, and are separate from freshwater systems. This also protects critical and essentially irreplaceable components in case of loss of electrical power to the boat of more than a few hours to a day. But remaining systems need to operate. The solution is twofold, insulate, and heat mechanical spaces.

To insulate, the first thing is to cut off air circulation into mechanical space. This means closing the large openings that allow combustion air into engine rooms, either by taping on cardboard or plastic sheeting covers, stuffing material into openings (pool floaties tubes work perfectly for my engine ventilation openings). Areas that hold plumbing can also be insulated by adding foil quilting or Styrofoam insulation to outer walls of hanging closets or under sink storage and even within the engine areas. This gets complicated, you need to be aware of risks of trapping condensation which can lead to structural damage or mold but even within insulation recommend ensuring the circulation of warmer air into these spaces via louvered or just held open doors and use of a fan in the larger adjoining space.

To heat mechanical area(s) (engines, HVAC, batteries, freshwater system), I need to use a vapor safe (non-sparking) marine heater with lower power settings available than living space heaters (200-400 watts). This must always be kept on, be kept part of the core set of devices that get power no matter what. If there are multiple spaces, you need multiple heaters, or to winterize any unneeded subsystems.

There are several easily overlooked special cases. Wash down pumps, plumbing and pumps need to be drained or protected. Ditto for external showers or deck sinks and plumbing if not in a heated area. A deck refrigerator with cold drinks will turn into a freezer full of burst bottles and cans, and an ice-maker's water feed line will freeze. Blackwater can freeze as can toilets with water in plumbing or a bowl. Lazarettes may have freshwater plumbing and may have a dedicated bilge pump with a drain hose. I make sure the lazarette is not open to the outside air by stuffing vents, and use a small heat source or deliberate air leak from heated space to keep it above freezing which would damage the bilge pump or cause lines to choke with ice. It does help that bilges are in the bottom of the boat and contact with liquid water through the hull but they are also where cold air will collect.

If spaces are not exposed to the outside air through a hull above the waterline but are below the waterline, they will get some protection because water outside is above freezing, and typically there is some heat flow from occupied spaces into spaces below. My engine room is half below the waterline, and there is some insulation from fuel tanks which cover most of the hull walls, and acoustic insulation on all walls Other boats will have different arrangements.

A larger issue is just how best to insulate boats, both to achieve livable temperatures and reduce energy cost. Options range from just putting the plastic film over window openings, weatherstripping on doors and windows, and keeping curtains closed to keep in the heat, or opened to let in sunlight (my old houseboat had lots of glass, was hot in January in midday, frigid at night.) At the other extreme is wrapping the whole boat in a heat-shrink plastic bubble for the winter season, which I did last year for about $1500. It worked but was odd living in an egg with essentially no view of the outside. In between have seen solutions including covering houseboat decks in insulation, placing foil in all windows, insulating inside of the hull with Styrofoam or even glass wool.

Other options include increasing the available heat supply. That can mean adding more shore power, installing diesel fuel-fired heaters of the same type used to heat truck cabs with hot air or hot water heat distribution, putting in solid fuel heaters (not sure what marina policy is on this, but they are available in marine variants, and a bit of coal can go a long way). In my case, I can easily double my effective electrical capacity by adding some receptacles to a 24 amp circuit currently dedicated to HVAC that sits idle for half of the winter.

Note that we are in a borderline weather area. We have had recent winters with weeks of sub-freezing daytime temperatures and night times temp near 10 F. We have had historically weak daytime teens and night time below zero. But these were unusual and maybe becoming more so. At some point, we might have a hard cold spell and it will be necessary to focus on what is best for the boat, make sure nothing freezes or is damaged that can't be replaced. Bailing to living ashore may need to be an option, although it leaves the boat unsupervised when most needed.


I love snow, especially big snowstorms. However big snowstorms can sink boats, and one almost killed me when I slipped and fell off a boat into what should have been the river, but instead fell into a conveniently located dragon boat. I was able to get up and continue shoveling snow off my neighbor's boat while marveling at fate.

A storm during my time here sank a houseboat and another small cruiser. The house-barge was converted unwisely into a multi-story office-barge filled with filing cabinets and computers and topped with a massive AC unit. So one needs to have shovels available suitable for using on finger piers and boats, preferably plastic. I have a regular one and a child's toy shovel perfect for getting into the small corners onboard. In a major snowstorm, snow must be removed before it makes the boat top-heavy, one foot is probably OK, two feet is not, and also depends on how heavy/wet snow is. We have had lovely snow removal parties shoveling not only docks but neighbor's boats as needed.

Snow is not so bad to walk on but turns to ice if not cleared. Ice starts as ice and is difficult to remove especially with limitations on using salt. Ice on boat surfaces will generally melt off with sun and internal heat. Remove what can be removed, but depend primarily on good shoes (or bare feet which work amazingly well, for limited periods) and caution, awareness. As with COVID, don't go out onto icy docks or boat stairs without a very good reason. Using metal tools to remove ice from anything is a bad idea, will damage the boat, steps, dock concrete.

Ice on the water has happened in mortal memory, in thickness enough to damage boats. Marina has lots of ice eaters, submerged electric "fans" that circulate warmer water from below up around our boats, discouraging ice formation. a thin (less than 1/2 inch?) layer of ice film is not a threat, 6 inches would be a problem, especially if the whole ice sheet moves as a unit around docked boats. But we are protected pretty well by docks from the channel, and the ice eaters do a good job of creating open areas around boats.


We have had lots of little breaker trips which have knocked out individual boats or sections of the dock. These can happen in winter and are annoying but a half-hour or even longer interval is not going to do damage to boats, although may get uncomfortable onboard. A longer period of say twelve hours is serious, long enough for interior temperatures to fall to 30s or 40s. Boats with (working) generators should use them. Boats with working engines might also use them to generate heat, open up access doors as needed. Fortunately, the marina is pretty good about resets and some of us have received training to reset power ourselves with marina oversight. A larger power outage affecting the whole marina and beyond is unlikely; I can only think of one such incident when construction cut a buried cable. Again resort to generators, and if necessary leaving the boat to refuge onshore might be in order as we would do for hurricane events.


Old pictures of sailors in winter rarely showed them wearing shorts and sandals. They dressed for cold in layers as best they could and slept in their long johns. So when the boat gets into 50s and sometimes below, I wear underwear, tracksuit to sleep, plus more layers to be comfortable inside, and still more layers to be outside. I highly recommend an electric blanket for your bed and an electric mattress pad as well. Remember a little heat created and contained in the right place is much better than a lot of heat in the wrong places. My bathrobe is black, heavy velvet and has a hood, I look a bit like a medieval archbishop, or Darth Vader.

Boating is fun, but people who live on boats in the winter are more than a little crazy. The first question I get after admitting to living in a home that floats after the standard "Wow, that's cool" is "How do you manage in the winter? You must have a home on land."

Well, no, I don't. 


Winter Personal Safety Tips

  • Do NOT fall in the water - it can kill you.
  • Have one hand free for yourself as you board the boat - Try to avoid combining the acts of getting yourself on board and bringing things onboard if at all possible. Place objects on the boat, get on, then move the objects onward. Better yet, hand them up to someone else.
  • Shovel or sweep steps clean of ice and snow before walking on outdoor surfaces
  • Don't let ice form by walking on snow
  • Only use sand on ice on the docks and your boat, salt, unfortunately, is not good for either boats or concrete docks and is forbidden in our marina
  • Carry a whistle on a lanyard, perhaps along with your gate key
  • Carry a cell phone in a water-resistant case with a lanyard
  • Wear appropriate shoes
  • Be prepared to help save a neighbor from the water - locate and be prepared to use the lines, floatation, ladders, and platforms on the docks

Winter Boat/Vessel Tips:

  • Inspect all shore power connections before and after the winter season: 
    1. Turn off power at dock pedestal,
    2. Unplug each connection from the dock back to the boat and look for signs of corrosion on blades, heat discoloration, or melting around blade bases and sockets. 
    3. If there is any damage, replace the pair since the damage is likely in both the plug and the receptacle. 
    4. Apply anti-corrosion electrical grease to pins 
    5. Reconnect. Turn on the power. 
  • Do NOT let a fire start 
  • Check all electric connections visually and by touch
    • Dock to boat
    • Boat to heaters
    • Boat to all devices
    • Disconnect all unnecessary and especially suspicious electrical connection
  • Winterize propulsion and all summer systems
  • Insulate - windows, doors, walls + close and seal engine openings,
  • Add fans and dehumidifying to reduce condensation
  • Heat - add the safest space heaters possible
Winter Precipitation Tips (snow, and ice): 
  • Plastic shovels or brooms for onboard and on docks - NO metal
  • Remove snow before walking onboard and on docks
  • Accumulation is dangerous for boats - 1 foot of light snow is okay, 2 feet or heavy snow is not
  • Help your neighbors by clearing what you can
  • Our Marina installs ice eaters that keep ice away from the docks and, subsequently but not primarily, away from our boats
Winter Power Loss Tips:
  • Short - less than a few hours - not serious and relatively frequent
    • Call security for a reset
    • Some residents also are trained to reset power with management oversight
  • Long - a few hours or more - extremely rare
    • Turn on generators
    • Turn on engines
    • Seek shelter if necessary
Winter Clothing Tips:
  • Layers to wear inside the boat and out
  • Wool / Tech fabrics
  • Electric blanket
  • Electric mattress pad
  • Large hooded bathrobe