Join Date: Nov 2007
Location: SF Bay area
Thanked 7 Times in 6 Posts
Rep Power: 13
That's a scary story, though it reminds me that a bucket of seawater is a good way to temporarily de-ice the docks.
As to the OP's question, packed snow is about 30% as dense as water. So if I want to displace an inch more water I need roughly three inches of packed snow on the deck (my hull is not a cylinder but whatever). Fortunately the snow that falls isn't all packed, so in practice it's probably quite a bit more snow required to raise the waterline by an inch.
If I set up a boom tent and get negligible snow buildup around it, I might get 40% (10' boom on a 27' deck, bow is not very wide) less snow buildup overall so I'd need seven or eight inches of snow to get the same average rise in waterline, and as Bubblehead points out, it would be lifting many of the through-hulls out of the water (though hard to tell how much because you're fighting against the fore-and-aft righting moment of the keel).
s/v Laelia - 1978 Pearson 365 ketch