Limited sail trim controls, light to very light winds

Joe · Oct 8, 2015

I suggest you ease the outhaul a bit... watching the lower tell tale... and not focus too much on the top tell tale. If the lower tell tale starts stalling... then perhaps flatten the outhaul just enough to get it flowing again...... My experience in light air is to let the boat tell you what it likes rather than fixate on a written set of instructions.
In light air, I ease everything... then slowly trim in if the tales are stalling....and ... watch the speedo when you make adjustments.
I don't think twisting off the top of the sail in light air is as productive as you think... you need power and attached air flow over the largest part of the sail.... in light air you will never get the top tell tale to flow consistently...
I would also ease the halyard a bit... On the headsail, you can rig something to close the leech ... like a spinnaker's "tweeker".... But at some point in time a short jib car track would be a terrific upgrade to your system.

Jackdaw · Oct 8, 2015

I like this thread. Anyone can sail in 12 knots of breeze. Show me a person who wins a race in fluky shifty 1-3 and I'll show respect.

Joe got the sail parts right.

First lets define terms. For a lake sailor, VERY LIGHT means 0 to 3(ish), and LIGHT means 3(ish) to 6knots.

Let's focus on very light. The KEY is to realize that this is much more than a trim problem. Keep the boat moving. Boat movement generates its own apparent wind, which is its own reward. Watch your heading. If you can, focus on reaching as close hauled will stall and too deep kills the apparent wind. 50 degrees TWA is ideal, and you can come up slightly as you build speed.

Connect the dots. Look for wind on the water and sail to it. Try and always stay in pressure. Avoid glassy windless areas.

Trim, drive, and sit on the low side to heel the boat to leeward. This decreases the wetted surface area of the hull reducing friction, and also tips the rig so gravity helps add and maintain the sails shape.

If you can TRIM BY HAND... take the sheet in your hand and trim like that. Develop feel as to where to place the clew to keep the sail full.

Use a rigid vang or boomkicker to help support the boom and mainsail shape. Use your tells tails to maintain flow.

Focus focus!

Don Guillette · Oct 8, 2015

Sublime:You have enough sail trim controls to get the job done. I'll just elaborate a bit on what Joe from San Diego and Jackdaw has told you.Very light and light winds are 2 different situations. If you can sail in those conditions you can sail in anything because those conditions require a gentle touch and knowledge of what the sail trim controls for the main and jib are actually doing. Two points - the cunningham is a substitute for the halyard and I think your boat is a fractional rig so you're correct on focusing on the main because that's your engine.

Very light air is when you're barely moving. You're one step away from drifting. In that condition you need the sails as flat as possible because the wind doesn't have the power to get around the sail. It stalls about halfway across the sails.Forgot about the telltales in those conditions, they're not going anywhere beyond limp anyway. The object is to get the boat moving so crank on the boom vang and outhaul (reduce twist). Ease the halyard a tad.Twist is a speed killer in very light conditions. To see what's happening, form you right hand as if you were going to salute. Now twist your fingers only to the right. The top 1/3 is spilling air (power) so when you twist off in very light air your defeating your purpose. In fact, anytime you twist off the sail you're spilling power.

Now let's assume you've got the boat moving If the wind does not start to pipe up then don't do anything with the controls -- just be happy your moving!! Let's say the conditions start to improve. VERY GRADUALLY ease the outhaul to induce a little belly (draft depth). Go little steps at a time to wait for the adjustment to kick in. It's like adjusting the temperature in the shower or adjusting carb jets (when engines had jets) - you have to wait for the adjustment to take hold. In very light conditions, the telltales will probably be flopping all over the place so just concentrate on keeping your speed steady (what little you'll have).

As far as the wind at the top of the mast - it's about 60% higher then at deck level, which is not a factor in the conditions we're discussing because there is no wind. The difference is cause by friction - the water causes the wind to slow at deck level so what you feel on your neck at deck level is not what's going on at the top of the mast.
I hope I haven't confused. anyone with my non scientific explanation .

shemandr · Oct 8, 2015

The question of twist in the upper main has been the subject of many posts here.
I'll take a swing at it. Worst case I'll learn something. There is likely more wind velocity at the top of the sail and you want that roachy main to make the most of it. I think it is all about attached flow. As you noted you can get better flow on top with a little twist. For pointing most sources recommend that the top tell tail be stalled about half the time. It is not that the stalling is desirable in regard to flow. It is to make sure the sail is on the edge of over trimmed and not the worse condition, the edge of under trimmed . But throw that rule out in light air where the game is to get the boat moving. Pointing is a secondary goal.
Closed leech is the more powerful shape but if it's stalled up top it's adding dreaded drag. So it hurts two ways. So if that upper tell tail is streaming, I think you are correctly trimmed for light air. The other boats? Those are other boats.

Don Guillette · Oct 8, 2015

The sailmaker has to build twist into the top 1/3 of the sail or a mate would have an awful time controlling the sails. I don't know about having the top mainsail telltale stall half the time. To me the most important mainsail telltale is the top one because it's your twist indicator -- the most important jib telltales to me are the middle one. Let's see what Jackdaw has to say. He's much more scientific than I am and I'll defer to him.

Sublime: Don't forget your jib in the conditions we're discussing.

Jackdaw · Oct 9, 2015

As noted, normally the wind speed is higher at the top of the sail vs the bottom. Remember that with higher wind speed, the apparent wind direction always goes aft. Because of this, the apparent wind goes AFT as you move up the sail. This means more twist in the upper portion of the sail to allow the all sections of the sail to match the apparent wind angle they feel.

You are absolutely correct to do this by reading your tell tails.

Your lack of traveler hurts you here, normally you adjust that first when trimming. Not being able to bring your boom to the centerline as you ease the main to add twist will negitively effect your ability to trim.

So watch your tell tails and adjust the best you can!

Jackdaw · Oct 9, 2015

On flickering mainsail telltails.

In light to med air pointing or reaching, all tell tails should stream.

Close hauled in solid breeze (9-14 true) the main should be trimmed in so the top telltail flickers back about half the time. That's best upwind trim.