While Greenbird will definitely be a higher-performance option, I wouldn't go with it because I'm too cautious in terms of what can go wrong when things really get hairy.

  The hard wing sail is going to be faster than a soft wing, and also create less windage in most scenarios, even in most storms, assuming the camber is flat and the tail feathers the mast properly.

  However, if the mast bearings fail in a big blow, or if the wing doesn't feather quickly enough in response to a rogue gust from a different direction, that could be the end of the mast and/or boat.  This can work on something like saildrone that can be knocked down and pop back up, but a multihull doesn't have the ability to reduce the rig stress by heeling so gracefully.

  That's something I wouldn't be comfortable with when too far away from shore to swim to safety.  Planesail, once the poster-child for hard wings weathering hurricanes, was dismasted in 2004.

  So, the hard wing is better most of the time, but failure of the mechanism could be a disaster.

  For that reason I'd go with something that's easy to reef.  The bare pole will represent more windage than the hard wing when things are working smoothly, but a whole lot less windage if the bearings fail.

  Right now the Advanced Wing Systems looks like the simplest and most robust design to date.
 

        - Mike

 

so how do people feel about this sail vs Greenbird
likes dislikes, comparisons, structural issues etc

Personally, I was surprised a little that a flexible skin had been found that enabled some way of collapsing the sail, and somehow I still hanker for the potentials for the Greenbird rig

is it just me being a moron or?