I really do think we need to seperate the 2-up from the 1-up sailing when trapping under spinnaker.
In my typical conditions and boat (Modified Taipan). Trapping downwind solo is dangerous and hardly ever worth it in a race. I found that sitting in, going a little high to pick up speed and then turning down deep while keeping the luff hull flying is waaaay fastest (for me). I go both deep and fast; it reminds me alot of how one sails downwind on a landyacht. Speed is everything and when you have speed you can really turn the boat downwind and get both. When overstepping a mark in relatively flat water conditions or when forced to sail high in a distance race with medium winds; then by all means try to trap under spi solo.
When 2-up however, I found out what Stephen comments on with respect to the Tornado/F18. Put the lightest crew member on the trapeze and have him or her stand behind the skipper or even to the rear of the skipper (the back of the boat). If the skipper knows his job and doesn't wait for the gust to hit before turning down to ease the impact then this setup will be one fast ride. I wrote lightest person as when I do it at 85-90 kg I still load up the platform too much and pushs the boats in before the luff hull is raised out of the water. When we do it with the 60-70 kg crew then everything is fine. What a difference 15-20 kg can make, right ? In my experience, double trapping under spinnaker simply doesn't work on the F16 for a score of reasons. Note however that I rarely double trap upwind either. I found that putting the heavy guy on the wire and having the lightest person steer works best upwind on my boat. We can keep the luff hull out more consistantly that way and don't load up the rig too much so that it flattens beyond the point you want.
Personally, I always found that the F16's (both modified Taipans and VWM Blades) want to stream rather then be loaded up. More often then not it is better to single trap when 2-up then double trap. Open the rig and let it breath (stream) rather then closing it up to keep 2 out on the wire. I feel only light crews can get away with double trapping. Although I must say that the best F16 so far under 2-up trapping was the VWM Blade in the Alter Cup 2007 fitting (Glaser sails). That actually appeared to keep both of us (73kg + 85kg = 158 kg) on the wire and stay ahead of a new Nacra Infusion with the club champs on it.
I feel the F16's on downwind legs are no different, they just show this phenomenon earlier. So what Matt?Gina do, getting in the middle of the tramp, lift the luff hull and drive deep and fast seems to be a mode that is well suited to spi sailing on the F16's. When single handing the crew does the same but hikes off the luff hull.
Ohh before I forget. Last year during the NAM-REM race we had to worst conditions for F16 sailing and even the F18's were struggling to keep the spi up in the first long leg (a high broad reach in SEVERE wave height chop) to the turning mark. The F18's could just make in one straight line (although quite a few pitchpoled) but we simply couldn't (VWM Blade + Ashby sails + Landenberger spi). So we started experimenting, to reduce the potential race damage. We came up with the solution of beam reaching to a point sufficiently high to make the mark under spi. This had the added advantage of clear winds. And then Put the 85 kg crew (me) on the luff hull against the rear beam and working the spi with the skipper below me on the tramp and also against the rear beam. I would call all the gusts (small and normal, big, very big) to the feel on the spi sheet and my skipper would immediately react by starting to turn down proportionally. Just before the gust ended he would steer up again. We snaked under spinnaker on a high broad reach like that for many kilometers and never flipped. We came really close a few times but the follow rule always works on the F16 :
If you are at the back off the boat and stay there then during a dive , then you will survive.
We submerged the leeward bow many times but often kept the speed up. But this was "easy" to do with the chop that was of wave height. We crashed through many a wave, but we did so with speed. This tandem sit was noticeably better then sitting side by side on the luff hull. What a difference 0.5 mtr can make huh ? And I feel it will become one of the standard procedures for my F16 sailing.
Also note that the tandem sit really allows both skipper and crew to pin themselves to the boat. I had my foot against the sidestay and grapped the rearbeam from time to time when the ride became alot like a rollercoaster. The skipper had his foot against the traveller cleat and the other (with bend leg) under the hiking strap I believe. Did I say we really did crash through some waves ? I remember getting hit a few times by a wall of water but we kept upright, stayed in our positions and kept speed up.
Maybe this is of some help to you guys ?
Wouter
