Hi Folks!
Answering:
@RobH, yes my gooseneck attaches to the sailtrack on the back of the mast - it slides into a section that is a bit wider, same thing I use to bend the sail to the mast. Except for the slot portion, it can go as high or low as I want it. Occasionally I put it up above the slot (and pull the clew end up with my topping lift) just to get everything way up out of the way if I'm motoring. Yeah, boom downhaul wouldn't work if the gooseneck can't move up/down. For what it's worth, the wrinkles at the foot of the sail don't really matter, that whole area gets more turbulence than anywhere else on the sailplan. My mainsail is pretty much an old bag, so I'm more interested in getting that diagonal crease out, and moving the max draft point forward, which you can do with a "normal" Cunningham as well.
@GL: My geometry works out for the boom downhaul not interfering with the vang. As I wrote somewhere else, I use a 20:1 vang setup and it attaches to the boom about 3 feet back from the mast, so enough space. How often do I adjust the downhaul? I'd say about 3-4 times per outing. I try to trim the sail to not have "bad" wrinkles (see note) and get the draft where I want it. Also I don't have reef points, so if I need to depower it has to be via sail shape (and luffing and eventually dropping the jib, ugh). As the wind gets stronger, I crank down on the downhaul - and outhaul, and vang - at least when reaching or beating upwind. When I come off the wind - broad reaching or running - I'll ease the downhaul again, outhaul too depending on wind speed, so the draft deepens and moves back towards the leech. I'm still playing with vang steering, so how much I use the vang vs downhaul all depends. Anyway, since my usual afternoon's sail is upwind as far as I feel like going then run home, that means only a few adjustments to the downhaul. I'll also slack the downhaul/outhaul as the wind dies down.
Perversely enough, in near-drifting conditions, ghosting along, I tighten up the boom downhaul again and give it some outhaul, at least upwind. Sometimes I'll also pull the clew up with my topping lift, anything to get a "clean foil" into the little wind that I have. I don't want to waste any wind energy shaping the sail, so I shape it with my "strings" and hope for a puff. Does it really make a difference? Jury is still out, hard to tell with no GPS, but it gives me something to do besides whistling for more wind!
Lastly, answering obvious question - where do I want the draft? Judging the distance from luff to leech, I want it about 40% of the way back most of the time when beating or reaching, further back 50-60% in lighter air (maybe <8 knots) or running, further forward 30%-ish for heavier winds (for me, that's >20 knots), back to 40%ish for ghosting. I plan to put a draft stripe on my sails one of these days, but for now I just eyeball it by staring upwards with my head as near to the boom as I can get while also steering and tending the sheets. Basically, I'm winging it! Not racing, so it's just for fun anyway. In practice, I'm usually sailing along and wondering why the hell I'm so slow when there's a decent wind and everyone else is zipping along... then I remember that I left the draft point way the heck back and need to tighten the downhaul. Or else it's something completely different I'm screwing up, usually sail twist
. Tune a few things, hike my butt out further and she's humming along again! Call me crazy, but I enjoy chasing after that elusive "perfect sail run."
Note: No marconi-shaped dacron sail is ever 100% wrinkle free, see this:
https://www.northsails.com/sailing/en/2 ... nkles-fastBest,
Tom