how to judge appropriate draft in very light winds?

[danstanford]

If a sailor can sail in light air they can sail in anything. The main sheet trimmer is responsible for the traveler, outhaul, halyard (or cunnigham) and boom vang. The jib trimmer can't be asleep. On a masthead rig, he's calling the shots and the main trimmer has to match his moves. On a fractional rig the jib trimmer has to match the main trimmer.

The following are my opinions and are general in nature and have to be tweaked to any particular boat plus they are not in any particular order.

The first thing I'd install are telltails on both sides of the middle of the mainsail. I also added telltails to the side stays which helped me stay "in the groove".

Keep the mast straight - forget the backstay. The traveler should be almost centered. There's a technique called "trim to a point of draw". The trimmer eases the sheet until the luff ripple and then trim in until the ripple just stop. Ease the main halyard slightly, which will move the draft position to about 50% to 55%. A cunningham is a better devise than the halyard and easier to deal with.

Ease the outhaul slightly. Here's the most important aspect to keep in your mind when sailing in light air. In light air the wind just doesn't have enough power to get around both sides of the sail and one side stalls. How many times have you seen boats trying to sail in light air with a lot of draft in the main mistakenly thinking they are grabbing as much of the little air available and going nowhere!! So you have to be ever watchful that the wind, whatever little there is, doesn't become detached.

if you have a vang release it - you want the boom to rise slightly. In light air you can cheat with the topping lift. If you have a leech line - tighten it because you don't want the leech fluttering.

Twist is a speed killer in any wind speed and deadly in light air- eliminate all twist..

What I've provided is contained in my SAIL TRIM CHART. Light wind is one thing but as the wind increases all the setting change accordingly and the SAIL TRIM CHART outlines the new adjustments for both the main and jib.

We had a race last night which started with almost all the boats unable to get over the line and many that fell back across the line due to 0.0 knots of wind. The Race Committee left us there until some of the lighter boats like mine started to gain a bit of way and therefore apparent wind as well and got to moving toward the mark. We saw perhaps half a knot indicated by my instruments and got up to an almost walking speed but you really couldn't even tell wind direction it was so light. Eventually we got up to 2 kts and really started cooking but the only boats really moving were light ones until the the breeze got up to over 3 kts.
The reason to post this was to talk about the point made above about twist. Once we got the telltales flicking a bit we could understand the amount of shear present and really wanted to add twist to accommodate this but the boom was so heavy as to pull all the twist out. Had I had a topping lift I would have used it for sure. In the end we got moving by having the main trimmer using his hand to control the boom position and to try and keep some flow attached.

 

[shemandr]

I'll throw this into the mix:
I think Buddy Melges was not a big fan of the concept of twist. I should say of twist of the wind - not the sail. He did not think there was much significance to the difference between the angle of the wind at deck level as opposed to at the top of the mast. He went on to say the forward and aft motion of the mast from waves had a much more significance for what wind the sails see. He advocated trimming the sails for the best middle of the sail trim possible and not to chase twist in the wind by adjusting the twist of the sail.
I really hope I am not misquoting the Wizard - I have to admit I read his book 20 years ago. But I took note because it was an unconventional viewpoint.
I've never sailed a J88 so I'll accept Dan's experience on the water as a fact. I would like to remind the discussion that while sail trim is very important, boat trim is too. You may find that the difference between boats that move in light air and those that don't is where the crew is sitting, how many crew there are, how effectively the weight management is and how clean the Botton is.. All of these parameters are typically overlooked in casual racing.

 

[danstanford]

I'll throw this into the mix:
I think Buddy Melges was not a big fan of the concept of twist. I should say of twist of the wind - not the sail. He did not think there was much significance to the difference between the angle of the wind at deck level as opposed to at the top of the mast. He went on to say the forward and aft motion of the mast from waves had a much more significance for what wind the sails see. He advocated trimming the sails for the best middle of the sail trim possible and not to chase twist in the wind by adjusting the twist of the sail.
I really hope I am not misquoting the Wizard - I have to admit I read his book 20 years ago. But I took note because it was an unconventional viewpoint.
I've never sailed a J88 so I'll accept Dan's experience on the water as a fact. I would like to remind the discussion that while sail trim is very important, boat trim is too. You may find that the difference between boats that move in light air and those that don't is where the crew is sitting, how many crew there are, how effectively the weight management is and how clean the Botton is.. All of these parameters are typically overlooked in casual racing.

We were responding to the leech telltales on the main and trying to get flow, as little as there was, to be even. Consistently the top telltales would wrap around behind the sail when the middle ones would fly straight back. As always, this told me to add twist till the tops ones flew 50% or more. We do have a square top main which may make a difference to our results vs others.

Somewhat related to your last point, when we were moving the windex would flow straight back as if we were going straight up wind though we could see from other boats that the true wind was at a pretty good angle. Our boat is pretty slippery and only 2 boats beat us to the top mark and both were smaller and lighter.

This was the lightest breeze you could have, zero to occasionally enough to spin the anemometer. Were it not a race, and were we not leading the series, we would have just headed back to some cold beer!

 

[Don Guillette]

I'll throw this into the mix:
Iwpoint.
I've never sailed a J88 so I'll accept Dan's experience on the water as a fact. I would like to remind the discussion that while sail trim is very important, boat trim is too. You may find that the difference between boats that move in light air and those that don't is where the crew is sitting, how many crew there are, how effectively the weight management is and how clean the Botton is.. All of these parameters are typically overlooked in casual racing.

Shermandr, as always, brings up a good point about crew position. My SAIL TRIM CHART list 14 factors for the mainsail and 5 for the jib that need to be set not only for light wind but every wind speed and point of sail - that's a lot of stuff to check!! As Shermandr mentioned crew position is often missed as is batten and leech line adjustment. Most beginner to intermediate sailors or middle to back of the pack racers can't memorize all the settings (I couldn't) no more than a football coach can memorize all the plays or a pilot all the settings - they use a check sheet.

If you've paid a race fee why not set your boat up as perfectly for the conditions as you can. If you do you won't be in the middle of the pack for very long because every race boat I've been on forget adjustment stuff. The farther back in the pack they are the more they forget. That's why they're in the middle of the pack because they're guessing at adjustments. Some settings they come up with are working against each other. It's like slamming a sports car into second gear, flooring the accelerator and pulling up the emergency brake. How do I know they forget stuff - I bring my check sheet.

NOTE: Sailboatowners.com is out of my charts but I'm shipping them a new supply today.