Jib downhaul:

I have to admit that I've never sailed a cat with an adjustable jib downhaul and it seems that all the go fast boats have them so I have to assume that understanding how to use it helps you go fast...

Being very naive, I would assume that honking on the jib DH flattens the jib just as honking on the main's DH flattens the main, but I suspect it's not all that simple. With the main's DH, you end up bending the mast which is what really flattens the sail. So I'm not sure I see how a jib DH would flatten the jib. Maybe by tightening the luff of the jib it's giving it less "sag" and therefore less shape... That raises the question of whether changing jib DH tension also changes the effective forestay tension, the overall rig tension, and the effects that those may have...

Then there's the whole issue of moving the draft. As I recall, on the main, adding DH moves the draft forward, which I think I've read effectively makes the foil less powerful. If it does that, I'm now sure I understand why (I should have paid more attention at the time). I would assume the same thing happens for the jib?

Anyway, as you can see, a little bit of knowlege (and a larger lack of knowlege) is just plain dangerous. So this would be a great time for a short jib DH primer to set me straight. So what's it for, why does it work, and when do you adjust it? How much of a difference does it make?

Self tacking jib traveller:

In a recent post I read someone mention that the jib "barber hauler" on a Blade's self tacking jib didn't help and actually hurt sail shape and power when it was used. I'm assuming they were referring to self tacking jib's traveller since I don't think Blades come with jib barber haulers. If I understood them correctly, they said if you just left it slack, the car found a decent sheeting angle automatically due to sheet tension and kept a better sail shape in the process.

So my question is have other people experienced the same thing? Is this issue related to a specific sail cut being slightly off, the self tracking track being bent or improperly shaped, is it boat specific, or maybe was the setup not optimized (ie, it would have worked better with more jib DH)?

So how do you guys adjust the jib traveller and jib sheet for upwind vs downwind? Do you actively ajust the jib traveller or just leave that line slack? Do you adjust the traveller and/or jib sheet differently for upwind vs downwind or pretty much set it and forget it? Do you do that differently for singlehanding vs doublehanding? Spi vs no Spi? Lighter vs heavier wind?

As a well respected sailor once said: "The questions remain the same; only the answers change"...

Jerry