Ok, I'm talking about mainly light to very light air in North American summer sailing. Some impressive boats like theM20 (Goran says you don't need a jib, but he doesn't sail here) and F18ht don't have jibs. Logic seems to indicate that with a high aspect main and spin you really don't need a jib. Of course the jib helps turn the boat quickly, but that can be overcome with improved technique. And it has been proven repeatedly by A-cats and others that the jib doesn't get you upwind any faster in most conditions. I say MOST conditions. My observation is that in light to very light wind the jib not only helps read the wind (see other post) but makes a big difference in speed. Much more than its area would suggest. I read that the I-20 substantially outperformed the f 18ht in light air (less than 5kt?) and I don't think it is just because of more sail area. They have a LOT more weight, which usually kills light air performance. I hate to pose such a subjective question, but I would like some indication that either my sailing technique needs a quantum leap in improvement, or that a jib is more than a crutch, at least in light air.