Fact or fallacy

[PGD]

I have been told on many an occasion that the water around your boat can act as insulation so that you engine is protected.

So why is it then that my toile pipes are frozen. Maybe because the marina is iced over ?

So does this tale only apply while on the river with flowing water ?

What do people think

Peter

cooking on gas - no way - running on diesel /forums/images/icons/wink.gif

 

[adarcy]

Not so much insulation as a large heat sink. People often mean seawater anyway
Basically, props shafts gearboxes or sterndrives will have some metal to metal contact from the engine block into the water. So if it is -3 to -5C in the air the engine will be closer to the temp of the water.
If we take freezing point of fresh water as 0C and sea water circa -5C I think it makes no difference to the point of greatest density of 4C.
Moving water delays the onset of freezing - kinetice energy etc.
Therefore stiil fresh water in a river marina will freeze at a higher temp than running or sea water but, in either case, it is likely that the metal "heat sink" will be sitting in denser warmer water under the ice. Sure the toilets can freeze but that's less expensive!

 

[ChrisP]

Had real trouble explaining this last week when the subject of theromstat settings on the engine room heaters etc came up. (mine are at +5C).

You done the job perfectly.
Thanks

ChrisP.

What do you mean the sea gull in front's walking !!!