Re: how big a tarp do I get?
I have a 23ft cuddy. I covered mine 2 weeks ago with a 20 X 30 tarp. I laos put in a few stands to help it shed the snow, and to help it breathe. By the time it was coverd and tied down I had about 2" of swm platform showing. The tarp is tied down to the trailer frame with 3/8" rope. Snug but not tight enough to rip the eyes out of the tarp. Itflutters slightly in th ewind but no flapping that will let the wind start a rip.
The stands are just 2 2X4 set in an X-pattern, a single 2x4 stands on top of the X-shape. On top of the standing 2x4 I made a circular shape so there would be no sharp edges to wear on the tarp. I made 3 stands in total. One is about 5ft high for just behind the windshield, a 4ft one for just ahead of the motor access cover and a 2ft high on for on top of the cuddy. Together they make a steep tent shape that should keep most if not all of the snow off.
The tarp I used is a black and silver from Princess Auto. I put the black out to help absorb any heat the sun may be giving.
Here is the type of boat I covered.