I added the gallon jugs 3/4 full of water- now their rock hard ice.
I keep the boat at an incline so that any moisture in it is back by the drain plug. I also have a small amount or road salt back in there too.
I didn't want any water freezing near/around the centereboard trunk inside- I theorize could easily lend to small cracks/seperations.

We've already had about 6" snow, but it has all but evaporated/melted.

Awaiting the winter snow falls