The Hobie 16 spi is the official ISAF youth boat at this time; thus hobie made it class legal in order to not loose this particular beneficial usage. Will be replaced by the SL16 in I think 2007 though. A purpose designed youth boat with spi.

Anyway, back to topic.

Sailing fast with a spinnaker is something you will have to learn. You can both sail too low and too high with a spi and indeed loose out to a boat without a spi that sails very deep. The trick to spi sailing is that you luff this your spi really powers up and makes the boat accellerate. Than you steer down in such a way that you keep your speed up but at much lower angle. Here you ride the boat so that you keep your speed up. If you make an error then you'll can fall off the groove and have to start all over again. In the beginning you will fall off the groove often. You really have to develop a feeling for the spi and boat so that you promptly make the right steering actions all the way down the downwind leg. If you do it right then you'll be continiously making S-curves; this is called snaking downwind. You can really see in the foam track you'll make how pronounced the S-curve can be, especially in gusty conditions. Also proper sheeting is very important, the crew must continiously look for the maximum curvature that doesn't allow the spi to collapse. If he or she does do that then he can quickly pull all the power out of the spi. Then sheeting out a little can make a big difference in the power and drive developped. the spi is certainly not a set and forget sail. Downwind sailing with a spi is many times more dynamic then downwind sailing without it. You are sailing with apparent wind coming from the side or even forward instead of it coming from the rear. If you are not continiously working the boat and spi then you will never reach the full speed potential.

In 17 knots of wind you should be able to sail the luff hull clear of the water for all time.

When new to spi sailing you'll often find that you are slower than a well sailing spi-less boat, however when you get better in optimizing the handling then you'll find that you can increasingly sail away from the old setups. In the end you'll leave them for dead.

Also practice on your hoist and douces alot. This is of a little importance the larger scheme of things but still alot can be won by doing it right and fast. Especially being able to hold the spi nearly all the way to the bottom mark can win you alot of time.

Sometimes, conditions can prevent the spi boat from reaching its maximum performance. This is nearly never the wind and nearly always the seastate. Example : One time we were racing in 1.5 mtr waves with a very short wave length, winds about 12 knots. The non-spi boats could surf a single wave all the down to the mark, while the spi boats just didn't have enough power to pass the waves. Actually you could if you sailed very high with the spi up but that killed downwind VMG. End result, the non spi boat could stay very close to the spi boats. Sometimes this happens, and then you just have to live with it. Although the non-spi boat were still faster around the course, we just suffered badly on handicap

Good luck.

Wouter