It also helps to try to feel the 'pressure' in the kite/boat. After a while, you just switch on the autopilot and keep the hull airborne. We did quite a few sessions with crew on leward hull just working on getting the feel for when to head up again. You need to have an agressive attitude (but dont yank on the tiller), and head up again a bit sooner than you are really comfortable with (as Maughan said).

Getting up to speed downwind is quite hard, as your crew probably must sheet out a tad as you fall off, and in again when you head up. You either must talk with each other continously, have spent some time on the boat together earlier or have a very attentive crew who watches the luff and telltales continously. I actually find it easier to go well downwind in a breeze when we can fly a hull, than in weaker winds. In weaker winds, we talk together a lot "heading up for speed", "falling off again" so the crew knows what I am doing and can trim the spi accordingly. That way I also get a second opinion on how much virtual wind we are drawing and how much further I can head down/up.


It looks like John had plenty of wind, so he did not need more power in the main to fly the hull, but not enough wind to break his mast. In those conditions, a twisted main is faster. If there had been less wind, I would have sheeted in a bit and moved down on the tramp to fly a hull. Also, if there had been more wind I would have sheeted in a lot more. As long as the main dont backwind, it's probably OK. If you get some decent breeze in Miami, you will probably see the guys with carbon sticks twist off their mains when they have enough power and want forwards motion on their downwind legs. You need to be a bit more careful with the alu mast, but many T skippers trims the main downwind with the alu mast as well (within limits!). What you want on downwind legs are forces sucking you forwards, but you can use the top of the mainsail as a trim-tab to lift your hull at the expense of added drag. This drag is compensated by decreasing your wet surface with 50% and gives about 25% less total drag. Hence it's faster in marginal conditions. In strong winds, the drag is not as bad as you have more virtual wind and you need to think about your masts integrity. The T probably also build a bit more virtual wind than the F-16's, so you need to lock out for backwinding.
At least, this is how I see it. If you trim the main for 50% aft streaming leech telltales downwind, you can't go much wrong as long as you drive the boat hot. I find it most difficult to know when to go hull flying and when to drive it flat. In weak winds, it's a constant evaluation for what will pay off, but only practice will give you that insight.