Flat winter cover for a B311

[amayers]

I'm going to need a winter cover for my B311 and saw an interesting cover this winter that was flat, rather than the usual aluminum frame with canvas tent.
The cover lay flat on the deck and cockpit with cutouts to go around stanchions and other protrusions. It was kept taut by bags of sand. It did not have a manufacturer or other tag I could see.
If anyone know who makes them I would be grateful.
Thanks,
Adam

 

[arf145]

One thing to keep in mind with such a cover is that it wouldn't help ward off condensation below like a tent-type structure would.

 

[amayers]

One thing to keep in mind with such a cover is that it wouldn't help ward off condensation below like a tent-type structure would.

thanks