The extra drag of the spinnaker snuffer system is what led Nacra to move the whole thing to the mid pole setup, as the Blade has. The original I20's all had the big hoop at the end of the pole and the entire spinnaker was hanging under the pole, if there were any waves the entire mess was soaking up water upwind, gaining weight of course. So they went to the mid pole system. For a long distance race, they used a skinny pole and tramp launched the spinnakers so there would be as little drag out there as possible. Marstrom went to the Snail snuffer system, to get the entire spinnaker out of the wind and water.

On the Uni vs. sloop thing. Back when a bunch of us in Florida all had Nacra 5.5's, there were several of both Uni and Sloops racing. The guys saling the Uni (solo, no jib) would usually beat the sloops to the windward mark, especially in light air. They could point higer and without the extra weight of the jib/bridal foil/crew, were lighter and beat us downwind too. Of course one of those guys was a several time National 5.5 Uni National Champion, he is now racing a Nacra A2. I asked him about adding a spinnaker, he said, "Why? It's fast enough the way it is and I don't want to spend an extra 30 minutes setting it up and taking it down."

It was then I started thinking that the small extra sail area of adding the jib, (54 feet?) did not add enough power to compensate for the extra weight of the crew. The only time the sloops would go faster than the Uni's was when it was really blowing and the Uni's were overpowered but the sloops weren't.

But when you add the coplexity of the spinnaker, the crew becomes vital for a good set, douse and of course trimming the spinnaker downwind. I would expect the sloop crews to be faster upwind in a blow as well, as long as the crew isn't too heavy for the wind strength. In light to medium wind, the F16 solo with spin. should be faster than the sloop, as long as the skipper can set and douse the spinnaker without giving up too much speed while doing it.

On the drag thing, you will notice that all the Olympic Tornado racing crews wear the streamlined pull-overs over their life jackets/trap harneses, just to reduce the drag of clothes flapping in the wind. <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />