How cold can I sleep onboard?

[DanielI]

We’d like to get out sailing for a few more days this season before hauling out, but lows in our area will be hitting the low 40s (highs around 70). Last time we slept over, it was still warm in the evening, and we went to bed with everything open, and woke up quite chilled.

I’m wondering, with no cabin heat, how low a temperature is reasonable to sleep onboard if we close everything up before we go to sleep?

[Lazerbrains]

Get a sleeping bag and you can sleep into sub freezing temps.

[longjonsilver]

Minus 25F

[Bill O]

Originally Posted by DanielI

We’d like to get out sailing for a few more days this season before hauling out, but lows in our area will be hitting the low 40s (highs around 70). Last time we slept over, it was still warm in the evening, and we went to bed with everything open, and woke up quite chilled.

I’m wondering, with no cabin heat, how low a temperature is reasonable to sleep onboard if we close everything up before we go to sleep?

Where are you at and what is the water temp?

If the water is warmer and you close up the boat at night the interior will stay warmer. Since you don't have a heater, try a good sized oil lamp to take the chill off.

[TeddyDiver]

I lived in the distant past two years without heating. The coldest winter temperatures were -30deg C and when it was only -20C outside I openend the door to warm up the house some. I had the best sleeping bag what money could by those days, rated to -40C. Got so aclimatized to cold I could not stay in normal room temperature more than 20min.

[tkeithlu]

It's not how cold you can sleep in - a good sleeping bag and/or a warm friend solves that problem. It's what temperature are you willing to get up in? With no heater, the morning temperature is going to be at the balance between water temperature, air temperature, heat generated by bodies, and insulation. But then, bouncing about the cabin while staying inside your bag, as in a sack race, while you fumble with lighting the stove is just so much fun!

[Dsanduril]

But then, bouncing about the cabin while staying inside your bag, with your warm friend, is just so much fun!

There, FIFY

[Lodesman]

Originally Posted by Bill O

If the water is warmer and you close up the boat at night the interior will stay warmer. Since you don't have a heater, try a good sized oil lamp to take the chill off.

Please do not do this - don't want you to die from carbon monoxide. Will you have electricity? - A small ceramic heater in the sleeping area will make it more pleasant. Otherwise, sleeping bag, or numerous blankets.

[ChrisJHC]

There are people who go camping in -40 degrees.
They seem to survive, but it obviously takes a lot of preparation, knowledge and the right gear.

[JPA Cate]

Originally Posted by tkeithlu

It's not how cold you can sleep in - a good sleeping bag and/or a warm friend solves that problem. It's what temperature are you willing to get up in? With no heater, the morning temperature is going to be at the balance between water temperature, air temperature, heat generated by bodies, and insulation. But then, bouncing about the cabin while staying inside your bag, as in a sack race, while you fumble with lighting the stove is just so much fun!

tkeithlu's experience is similar to ours. Jim and I have spent our first winter down under, outside of the tropics. We found temps of -1 d. C on land, one morning cold enough to have ice on deck. We found ourselves sleeping in thermal underwear, and a sleeping bag would have been good. We were sleeping under a summer comforter, with blankets on top of it. I wore wool and polypropylene socks. When you get up the icy air has to warm before it touches your tender, astonished flesh. You may wear thermal underwear for months!

The other issue to address, is the boat will get condensation in it, and it gets like a rain forest below. One needs to insulate all the under deck area, down to the water line. We had various kinds of damage because we weren't really tuned into the problem beforehand. If we spend another winter down here, we certainly will have to make a more serious effort.

And, we do have a heater. We were using ~ 20 liters a week for charging batteries (short days, low sun angle, not much help from solar panels, lots of cloud) and heating the saloon. (The latitude is 43 deg. south, so not really extreme. It is tropical acclimatization that is our underlying problem.)

Ann

[Jammer]

Originally Posted by DanielI

I’m wondering, with no cabin heat, how low a temperature is reasonable to sleep onboard if we close everything up before we go to sleep?

There are a handful of liveaboards in the St. Paul (Minnesota) suburbs who stay on their boats all winter. Typical low temps on the coldest night of the year are around -15 to -20 F. But I don't think that is, as you say, "reasonable."


I would say that most people with average tolerance for the cold will do OK with outside air temperatures down to around 30 degrees F at night as long as the days are sunny and warm and get up above 50 F or so. Use a good sleeping bag and have some hot chocolate and hot food in the morning and you'll be fine. Interior temps will stay up around 45 or so which most people can tolerate, and you can open up during the day to dry things out a little.



Below that it's uncomfortable and there are problems with condensation and with water freezing and so on unless you have reliable cabin heat.

[Svsumurun]

We are usually one of the last boats near us to haul out ( except for the fishing guys that don't sleep on board) , and have spent m ,any a night in the 30s. The smaller the area the better , so if you sleep in the v berth , close off the salon. We have a bulkhead heater on this boat, but every previous one , a small cermanic electric heater was fine ... with good blankets or sleeping bag.
The time to pull out for the winter is when it doesn't warm up in the morning .. usually October it still gets up in the 60s pretty quick !

[dfelsent]

Originally Posted by tkeithlu

It's not how cold you can sleep in - a good sleeping bag and/or a warm friend solves that problem. It's what temperature are you willing to get up in? With no heater, the morning temperature is going to be at the balance between water temperature, air temperature, heat generated by bodies, and insulation. But then, bouncing about the cabin while staying inside your bag, as in a sack race, while you fumble with lighting the stove is just so much fun!

For me it’s what temperature am I willing to shower in?
A good sleeping bag, close up the cabin, and you’ll be cozy all night.
I won’t run a fuel powered heater while I sleep, even with a CO and smoke alarms.
I will run the eberspacher to dry things out in the morning or to make for a toasty comfy evening.

[Olly75]

I've just wintered in nz with no heating, it got down to 43 in the boat some nights which was doable but it's the condensation that's the killer. Mainly solved it with bubble wrap on the hatches, portlights, and on the uncored cabin sides with a down jacket and wooley hat until it warmed up in the day time. Also had a karcher window vac which helped.
Having said that, I'm not intending to do another winter with no heating!

[TrentePieds]

There is no such thing as "too cold" weather. But there is such a thing as "wrong clothes"

A small boat is NOT thermally equivalent to any kind of shore-based accommodation. A small boat is more like a bivouac pitched on the tundra.

Your environmental enemy is NOT the cold. It's lack of ventilation. Lack of ventilation causes condensation, whereas keeping the temperature WITHIN the boat the same as the ambient temperature WITHOUT, prevents condensation. Once you (or the boat) get(s) wet from condensation caused by your breathing of by any other kind of source, you'll have lost the battle, and hypothermia is a real possibility.

Furthermore, once things are wet, you have zero possibility of drying them out without artificial heat and things spiral downwards from there. Cooking should be done with open hatches and the boat should be thoroughly ventilated once the use of the stove has ceased.

Wear underwear appropriate for the ambient temperature. Changing clothes, including underwear, takes but a moment IF things are dry, and you'll just feel a chill on your skin, but you won't get chilled to the point where your body has to struggle to warm up again.

Use a proper sleeping bag designed and made for use in the arctic. Getting rid of accumulated body heat in the bag is really easy. Getting warm again if you chilled is really difficult. Although eating raw seal blubber helps, I'm told :-)!

So in summary: Keep the interior of the boat at ambient atmospheric temperature. Insulate your body from the cold - including the cold within the boat.

Someone else warned you against sleeping in an enclosed space with a naked flame heater going. Take that warning seriously!!!

My Beloved and I routinely sleep in our boat, a 30-footer, in temperatures down to the mid 30(F) in "normal" underwear and sweaters (or hoodies) worn within pretty pedestrian sleeping bag. As I've grown bald, I like the hoodie, because the scalp is "radiator" that can deprive you of body heat really quickly unless you keep it covered. On getting up in the morning, just making the coffee on a propane burner will bring the temperature in the boat up to the low 50s.

An old fisherman's dodge from the northern waters where I come from is to "crash all standing", i.e. just drop into your rack in your daytime clothes. Inuit - people who in my youth it were still called "Esquimos" without the least hint of racial slur - do that too within their igloos built from blocks of snow.

TrentePieds