Water tank in winter

[Quandary]

What I do to drain the tanks, boat on its cradle in the yard, connect hose to tank and fiddle about to get the other end to the bottom of the tank, turn on hose, to fill it, disconnect at tap end and walk it down to the slipway to get it lower than ground level. Go home for lunch. When hose stops running I take the residue out with the pump.
Similar procedure for calorifier and for flushing prior to launching.

 

[JumbleDuck]

I just leave the tanks as they are. Both flexible, so shouldn't care about a bit of icing up. Same with the hoses. I suppose the pumps might suffer, but so far they haven't, approximately 28 Scottish winters after I started doing this.

 

[thinwater]

You also put them away dry. You can't dry out the inside of a water tank, so it's a choice between leaving it full of water or leaving it damp and full of air. Would you rather drink out of a glass which had been under water for six months or sitting around damp for six months?

I get it completely dry. Shop vac and then leave the lid off (large opening) with a dehumidifier running. It is bone dry within a week. That might not be possible in all cases, but it works for me.

 

[JumbleDuck]

I get it completely dry. Shop vac and then leave the lid off (large opening) with a dehumidifier running. It is bone dry within a week. That might not be possible in all cases, but it works for me.

That would work. But for set-ups where it wouldn't, I'd take "wet" over" damp" any day.