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mhinnc · 29-11-2021, 04:51

Q. Is there a general rule of having a little lee-way, temperature wise, in winterizing a boat?

This summer we acquired a C&C 30. It is docked at East Beach/Norfolk.
The boat has a raw water Atomic 4 engine. It's our first boat with an inboard.

The forecast is for the air temp to drop to 31 deg F tonight. Specifically, the current forecast is: "Clear to partly cloudy. Low 31F. Winds WNW at 5 to 10 mph." The forecast is for the air temp to be a high of 47 deg F today.

This is the first sub 32 deg for this season. Original plans were to go up today anyway. (I'm 5 hours inland), but some things popped up that makes it a little difficult to get there today, but not impossible to get there by late this evening.

Does the inside boat temp (sunshine), help hold a little heat through the evening; does the water temp under the boat help provide any relevant warming? Should I drop everything and make a bee line for the boat to winterize it?

Thanks for any advice/insight.

**Pete7** · 29-11-2021, 04:56

Water temperature will have a major impact on the internal temperature. We know the water temperature will never drop below 5'c so don't bother doing anything to winterise the yacht, other than drop the genoa into the v berth and roll the main tightly up inside the mast. Finally give the engine a service,, but that's it.

Pete

**GordMay** · 29-11-2021, 05:10

I didn’t see mention of them, in the Service & Repair Manual [1], but the engine should have freeze plugs [2]
[1] Manual ➥ https://www.fdlaudubon.org/page19/as...epairMaint.pdf
[2] Replacing Freeze Plugs ➥ https://www.moyermarineforum.com/for...ead.php?t=5132
➥ https://www.moyermarineforum.com/for...ead.php?t=4130

Dr. D · 29-11-2021, 05:11

Find the closest observation point providing water temperature. It is likely well above freezing now.

Here is the Thomas Point Lighthouse info:

https://www.ndbc.noaa.gov/station_pa...?station=tplm2

You should be able to find one closer.

mhinnc · 29-11-2021, 05:37

Thank you, Pete.

Our previous boat was in a little warmer climate - the southern North Carolina area. Freezing temps were not a concern there. Your reply brings up another issue. The sails.

.

Previously, sails were only a concern for storms with high winds. Now, I'm thinking freezing rain and the added weight to the rigging. The rigging, which is in good repair, does get a workout under sail. On this boat I'm confident the rigging will adequately handle the substantial strain of the pulling of the sails in even high winds. But the downward pull of accumulated ice on the furled Genoa and booted main - I'm unsure of the effect of the change in force direction on the rigging.

The Genoa can come off furler, no problem. The boat doesn't have a mast furler, so the main sits under a boot on the boom. However, for the expected winter climate of the area (unlike farther north), is it worth removing all sails for a passing winter storm which may temporarily yield some ice? Surely an eighth inch of ice isn't as much as a concern as a half-inch of ice; as a general rule, how much ice buildup on the sails would be too much (if a generalization can be made.)

Also, I do plan to be back on the boat a few times throughout the winter, so the sails in the cabin might be an issue there. (Albeit, a larger boat someday would certainly solve that.

)

mhinnc · 29-11-2021, 06:31

Quote:

Originally Posted by Dr. D

Find the closest observation point providing water temperature. It is likely well above freezing now.

Just east of the Bay entrance is station 44099, which is the closest I can find to East Beach showing the water temp which is a little warmer than your link, which is toward the upper Bay area.

Thanks for the link. Good source, which left the place it held in my mind at one time (i.e., I forgot. )

Jebtrois · 29-11-2021, 06:56

Tonight is not going to be a hard freeze here. Your boat should be fine.
JEB

capt jgw · 29-11-2021, 07:25

Sea water freezes at around 27F depending on it's salinity. So 30F isn't going to harm anything with sea water in it. (I'm assuming you're in salt water, right?) Now fresh water like in the potable water system is a different matter. But again, the sea will be warmer than 32F and any sunlight will help too. Unless it's below freezing for a few days running you'll be fine. Up here in Michigan it will be below freezing for weeks at a time and often below 0F for days. And we're fresh water. So nearly all boats are hauled for the winter and we winterize everything. Consider yourself lucky being where you are.

Rohan · 29-11-2021, 07:39

Quote:

Originally Posted by Pete7

Water temperature will have a major impact on the internal temperature. We know the water temperature will never drop below 5'c so don't bother doing anything to winterise the yacht, other than drop the genoa into the v berth and roll the main tightly up inside the mast. Finally give the engine a service,, but that's it.

I agree as far as the engine goes, since the boat is in saltwater.

However, I don't know what systems the C&C 30 has, although I assume it's pretty basic. But if the OP has a water tank, and/or a head that uses fresh water, then those systems need to be winterized.

chris95040 · 29-11-2021, 07:45

I'd probably risk it too, particularly since you are sitting in the water as that buys you some buffer temperaturewise, but just remember that low temp is a prediction! How often are those spot-on? Maybe it'll be in the mid twenties!

Slightly off topic, but when it comes time to actually winterize that raw-water cooled engine care must be taken to ensure the thermostat has opened so you are flushing _all_ the engine's cooling passages with glycol, yeah? Guess you run it on seawater until its hot, then swap in the glycol?

Kentb · 29-11-2021, 08:52

General rule of thumb, if the water isn't frozen where your boat is sitting, it probably isn't freezing in your engine...
Atomic 4's have a plug in the side of the block, one in the manifold (Dont remember if there is one in the riser). And I believe one in the water pump... dont quote me on this though..
I have winterized a few different ones over the years. Save yourself the B.S. of dealing with removing the thermostat. DRAIN THE BLOCK and everything else that will drain (dont forget exhaust muffler if it has one), then run about 1-2 gallons of -100 below antifreeze through it and you are done. Some will make it into the block, because it is empty even if the thermostat is closed. Many dont understand the function of these thermostats are a "bypass" valve set up.. meaning that removing the thermostat does not guarantee the antifreeze will circulate into the block, as you just opened all the ports, allowing the fluid to flow wherever it wants.
Having winterized lots of boats (professionally for over a decade) simply draining the block (and anything else you can drain) then running antifreeze through gets it done. Everytime.
All you will need is a screwdriver, a bucket of antifreeze, a length of (5/8"??) hose and you can connect right to the back of the pump, start it up with the hose at the bottom of the bucket (or even the jug of antifreeze) and shut her down as soon as is it starts sucking air.

As a note I have also winterized non-running engines, and engines that cannot be drained due to access with recirculating pumps to operating temperature. But my above recommended procedure is the absolute fastest, cheapest, and reliable.

"Why -100 below? ITs not getting lower tha -10 where I live? " Sure you can use -75, -60, -50 to save a buck. Just remember you have no idea if there are pockets of water in there you are diluting. For my money I always went heavy on the antifreeze. Never a bust yet.

Ken Pole · 29-11-2021, 09:05

Having rebuilt my mid70s A4 and having to winterize annually (now on the hard or five more months), I think it's important to stress that when you buy anti-freeze, make sure you get the undiluted stuff.

guyrj33 · 29-11-2021, 09:31

The Atomic 4 has two drain ports on the water jacket side of the engine and one in the exhaust manifold.
Yes there are Freeze plugs, but don't count on them for freeze protection.
For you location in Virginia, you could just run a gallon of antifreeze through the engine and spray some fogging oil in the carb.
It's very likely that the drain plugs will be clogged with rust and be non functional. One could remove the alternator and then the water jacket cover and clean out the collected debris or one could just run the engine and wait for other signs like overheating next summer.

Tigue · 29-11-2021, 09:41

This is a good question as I wrestle with it every year. Based on what you said here I won't worry at all.

For the first time ever this year I've decided to not winterize my boat unless I foresee extreme conditions, each year I do it and question myself if it is worth the effort as I'm in the more temperate Pacific NW. However my lee-way is way more aggressive then yours. I have a remote temperature sensor on the boat and it will give me an alarm to my phone if temp in the cabin goes below 32 degrees. I consider 32 degrees for a short period of time (< 6 hours) is a non issue. But if I see a cold snap coming and a sustained day in and day out sub 25 degrees then I'll have to worry and get my butt down to the boat asap.