Buy some non-toxic antifreeze
. Run the engine
and get it up to temp. Use the hose that brings in seawater to cool the engine and stick in in the bottle of antifreeze
. When you see it come out the exhaust
, kill the engine.
Not a bad idea to change the oil
after you get the engine hot, then winterize after.
Yes, empty the water tanks
, the same way as when cruising - turn on the faucets
Make sure there is no water left. You can add non-toxic antifreeze here if you want, then flush well in spring. Same with waste tank. Make sure all faucets get drained and/or get antifreeze run through it. DRain the hot water tank!
Pull your batteries and put on a trickle charge,or maintainer, or leave on boat with same. I don't know where you are and what is cold.....
Strip your sails
to avoid unnecessary wear.
There's more, but you get the idea. probably a comprehensive checklist somewhere online like BoatUS.