Vanguard 15 dinghy stuff
The V-15 has a completely different hull shape than a 470! We have found that in running it is much faster to sail a higher angle yet still wing and wing with weight to windward. The skipper should be on windward (side opposite the main right now and heeling to that side slightly (10-15 degrees) to minimize wetted surface and get the sailhigher. He should also be holding the jib sheet in his forward hand behind and outside the shroud, and the mainsheet in his other hand, keeping the boom just off the shroud. The crew should have one hand (their whole body in heavy air) on the boom. As far as the jib constantly colapsing, at this point you should be steering to keep it full. If you think its going to colapse, head down more. Good luck, sail fast!