That's VERY interesting, Dave. How would the sail's all-up weight compare with an analogous dacron sail?
I had to chuckle at the video, watching that stout mast's head violently flicking back and forth. Clearly a video gremlin and not actually happening, but disconcerting nonetheless ;) 5 tons... stay out of that scow's way!
-Per
-----Original Message-----
From: polysail@polysail.com [harryproa] <harryproa@yahoogroups.com.au>
To: harryproa <harryproa@yahoogroups.com.au>
Sent: Tue, Nov 18, 2014 10:27 am
Subject: [harryproa] Re:: controlled self capsizing for cruiser
I don't know what this fact might mean in the conversation about controlled self capsizing, but we've only recently discovered that the low-cost polyethylene laminate (polytarp) sails that we've been making and selling to DIY builders for the last 18 years are only 90% the density of water as opposed to Dacron sails which are between 130 and 140% as dense as water. For most small wooden mono-hull craft, at least, having a sail that floats can make a significant difference in whether the craft turtles or not. However, we have yet to do capsize tests on craft longer than 16.' I suspect we would soon find out if the scow built by the Crystal River Boat Builders ever went over. That boat weighs roughly 10,000 lb., is 36' long, 12+' wide, and is powered by a 507 sq. ft. PolySail gaff main and a 135 sq. ft. PolySail jib. She recently did 8 knots on a return trip from Cedar Key.
Crystal River Boat Builders sailing the scow "Spirit". I think that they have additional video of that ocean voyage on Facebook or youtube if members might be interested.
Dave Gray
PolySail International
