We were able to cover the boat last weekend.  We use a homemade frame made of PVC pipes for plumbing, insulating foam and cable ties plus a cheap tarp from Home Depot. 

It worked pretty well last year.  We did have one major snow storm late in the season that caused one of the supporting 'hoops' to collapse.  This year we added another hoop and stringers between the hoops to spread the load.

The frame is made using larger black PVC pipes for the stand and a ridge pole.  'Y' connectors are used to create feet and T connectors connect the ridge pole and the supporting poles.  Grey PVC electrical conduit is used for the hoops.  They are fasted to pushpit, stanchions and pullpit with two extras tied to cleats.  A stringer of the same grey PVC conduite is fasted to each side.  The hopes are connected to the ridge pole with cable ties and all points of friction are wrapped in the pink insulating foam.

We will see how it goes for this year.