Just finished hunting around for ideas on this and settled on a bow hut because it is the lightest, cheapest building (provided you can make it yourself). There are some tents made from emt but when they get wide enough to fit a boat I wonder if they would hold snow plus when you are done you have a load of steel pipe to store.
Only pic I can find of one is this one. I have made a couple bows already and it is very easy. I took steel stakes and laid out the shape I wanted on my lawn then bent the 2 pieces of 1x3 spruce between them and put the 2x4 blocks (7") between them on edge and screwed each one with 2" screws from each side. Very quick and not much springback when removed from the stakes/mold. WHole thing will be attached to the ground on 2x12's that the boat blocking and stands will sit on.
Also building mine to work with a 40 x 60 tarp so the up and over length of it is less than 40'. Pricing some shrink wrap too but it will be more $ and does not really roll very well as mentioned above. You can store it and get a few years out of it though. Shrink would be nice for light and I Think the snow would slide off it more easily.
Materials from my lumber yard are going to be about $600 including tarp.
