DJ-

All I've ever done is ran some Sta Bil through the tanks on what I thought would be the last trip out. I turn the motor over about once a month just to make sure it's still got oil pressure and to move things around a bit,that's about it. You don't need to worry about anti-freeze, like you said, the boat's in the garage, out of the elements.  Also, it doesn't freeze and stay frozen here, we may dip into the 20's at night, but it usually warms up as soon as the sun comes out.

i like the occasional start up!!!! seems like if you can find a way to open up a closed loop cooling system with a drain or whatever that will get the water from the block...the other day i opened up a plug that was on the intake all the water drained out of the pump where i connect the hose when i run on the trailer...i make sure the tanks are pretty much emptyu and use sta-bil stuff works wonders, but i still like to fire up the motor occasionally...it doesnt really get to cold here in vegas, but you got to be prepared

I like rays reply. I am always down for a winter sweater run. Woudl't be the first. Well in my  boat maybe. But I have been out in the cold. So empty the tanks or fill them. Wat about the oil. Change it out. I know over the summer condensation builds up in the valve covers producing some moisture. Should that be a concern.
p.s. Skip when are you going to come play?

yeah mine is gunna see water every 6 weeks for an hour

WERE I to winterize, I'd do as Skip says. Fill the tanks, add Sta-Bil, run it so it gets into the carb(s), then use the Marvel Mystery Oil spray deal that GT uses. Not sure if I remember right, but I think he said spray it into the carbs with it running until it dies. I wouldn't bother draining the block, if it freezes that hard there in Bako, we all have bigger problems than a boat engine block.

Ray

And yeah, what's a sweater? Do you have a pic?

And turn your steering wheel lock to lock often, mine seized after 10 weeks !