PTP,
2-up I think one definately should go out on the trap if they know how to move around on the trap and stay attached to the boat more or less. The speed difference is huge and, in my experience, sitting on the hull as far back as possible still has the bows digging in and stopping the boat routinely. Need someone on the wire behind the rear beam to keep the bows up. Once that happens then SWEEET! You can fly! and things are actually more stable.
That is exactly how most of us have experienced it
Just sitting on the hull next to one another is NOT enough in a blow; that is if you want to go fast. The difference between a crew sitting next to the skipper or hanging behind the skipper on the trapeze (even when in toilet stance) is quite significant. If the crew can even get a little further back as you say and stand level with the rearbeam or use even the footstrap then things start to power and speed up alot and the skipper can drive it hard.
My advice is in line with PTP here, get that second person away from hugging the sidestay and on the trapeze when under spinnaker in a blow. When it is reall rough then a little trick my crew and me do is to have her trust her rear foot between the mainbeam and my rear end and have her grap my lifevest with her rear hand. She holds onto the sheet with her forward hand and I help her trim it. Once trimmed right I handle everything by steering. Then I'm not looking anywhere specific and just drive it by feel.
Only problem for the crew is that he or she one needs to trust the skipper to have a steady hand on the tiller; if your skipper is nervous and twichy on the tiller then by Gawd I refuse to go out on the wire under spinnaker ! Will feel like some stunt man in an action movie trying to hang on on the roof of a car while the bad guy is trying to shake him off !
Wouter