Originally Posted by sailingfool
The sail I have in mind is often referred to as an A1 as in Asymmetric Racing Spinnakers | Doyle Sailmakers
. Not having done the math, Ii would think an A1 on a CAt27 with a four four sprit would have 70% or more area than a cruising chute. combined with the convenience of a furler, this area makes the sail more useful in the light to mid winds. In higher winds, the price of sailing with a genoa is not so bad...
I agree your cruising chute is providing excellent drive in your photo, and a larger A1 would be dicey, but winds in the high teens to low 20s is not the sweet spot where most sailors are looking for more go anyway.
You also have to keep in mind that the difference is not just about sail area. JonEisenberg's sail looks almost like a symetric spinnaker being flown as a "cruising chute". It has very full shoulders which makes it more suitable for sailing deeper. Once it is used on hotter angles it will become less efficient. It will start to generate more heeling and less forward drive just as a symetric does when tight reaching. An A1 asymetric, on the other hand, has a flatter shape, and a draft position that is more suited to reaching, so the power it generates is more forward and less heeling. It is more suited to the angles you need to sail at when you are flyimg from a fixed point on centerline. There is no point in having a "running" sail shape when running results in the sail being blanketed by the main. Of course not all cruising chutes and asyms are the same. They doo build a-kites that have more downwind shapes, just as they build symetrics for reaching.
My chute is classified as an A2 because it is a bit smaller. It is short on the hoist to accomodate a furler or sock which I haven't bought yet. It is quite a bit smaller than my biggest symetric, but still generates plenty of power. (I wish I had a pic of us doing 7.5kts with it last summer!) The beauty of it is that it is far more manageable power than a symetric.