For those who looked at Danny's impressive work place cover, my boat slip cover is designed exactly like this. It is mounted on 10 pilings (five per side) with a heavy duty lintel across the five pilings on each side supporting the galvanized pipe arches. The material is heavy duty vinyl. A place called Big Top in Perry, Fl makes them. Unlike Danny, I had to get the State of Florida to issue a permit to cover tidal waters before construction could start. I have pictures of this monster (48 feet long by 16 feet wide with enough extra to come down seven feet on each side) flapping in a 15-knot breeze with ten men trying to get control as they installed it. It weighs more than Danny's and took all those men to haul in down the pier. At least one was bucked into the water while wrestling with it. I was driving a moving van while moving into the house and thus (wisely) wasn't there. I figure that a heavy damage from a hurricane could be avoided by slipping the tie-down lacings off and letting the whole thing fall into the water for later reinstallation by the same contractor crew. The pilings and framing would fare lots better without the "sail" laced to them. Oh, trawler-related you ask? Well, I can't begin to tell you how easy it is to work on the CALYPSO under this rig in the FL sun and how much less I HAVE to work on her compared to when she spent 365 days a year outside in San Diego. Rich Gano CALYPSO (GB42-295) Homeport Southport, FL I'd rather be cruisin'