Threshold/trigger to add main twist back in for very light conditions

[danstanford]

We have been quite successful in the light conditions by removing twist in both sails which adds power. Using the upper tell-tales on the leech of the main we know not to overtrim and stall the sail but we may be overtrimming and then dropping the traveler in the very light where we should be traveler up and adding some twist for drive.
How do you folks decide when to switch modes?

 

[Davidasailor26]

In light air you sometimes need more twist to handle the more aft apparent wind up high, where the true wind is a little stronger. If you’ve got the telltales along the full leech flowing you’re appropriately handling that. I don’t start to add more twist than is needed to keep the telltales flying until the boat starts to get overpowered. Then more twist helps spill a little air from up high. Until that point I figure whatever twist keeps the airflow connected (flying telltales) is probably optimal.

 

[Joe]

Twist depowers the sail. It will make it flatter.. in very light air, you often need a flatter sail to maintain flow attachment. Trust your tell tales and you speedo.

 

[Don Guillette]

In light air you sometimes need more twist to handle the more aft apparent wind up high, where the true wind is a little stronger. If you’ve got the telltales along the full leech flowing you’re appropriately handling that. I don’t start to add more twist than is needed to keep the telltales flying until the boat starts to get overpowered. Then more twist helps spill a little air from up high. Until that point I figure whatever twist keeps the airflow connected (flying telltales) is probably optimal.

There's an easier and quicker way to handle a overpowered boat instead of messing with twist or the set of your mainsail - just drop the traveler until the boat gets "on it's feet" or wherever you want it. If it's a gust, just wait until it passes and then put the traveler back to it's original position. Light conditions are tricky to sail in - in my opinion, if a sailor can sail in light conditions he can sail in anything. The reason is the light air sailors knows how to make all the sail controls on the main and jib work to his advantage.

 

[Eclectic]

Your question begs well .. questions.

Wind speed is not the only consideration when deciding twist.

Sea state and wind variations could call for twist in the lower ranges to provide constant drive.

If your too flat for wind variations etc. over trimming loses your attachment.

I suggest a book, " A Manual of Sail Trim" by Stuart H. Walker

He carefully lays out the interaction of sail control devices through the wind ranges while posing

common issues and solutions.

Very handy reference.

Best Regards

 

[Eclectic]

It is also possible to "choke the slot" with a traveler position that is too low especially in light air.

In this circumstance the proximity of the sails causes restricted flow between the jib and main but the tells
will still stream aft.

We usually work the traveler from low to high after everything else is set.

One or two inches at a time and wait for the change to settle in.

Move past the sweet spot to find its limits.

On our boats we use the outhaul and halyard tension to set the "flatness" of the main but you seem to be speaking specifically of twist in relation to the traveler.

Don't forget to keep having fun!

 

[Don Guillette]

[QUOTE="Eclectic, post: 1748448, member: 126506"
One or two inches at a time and wait for the change to settle in
[/QUOTE]
Good advise - especially "wait until change settles in". It applies to ALL sail trim control adjustment. So frequently a trimmer expects.an immediate result from a sail trim adjustment. The following analogy doesn't work anymore especially with folks way younger than me. In my day, cars were much simpler. My Lincoln Aviator has gismo stuff on it I still don't know how to operate - nothing as simple as a 50's & 60's Chevy or Ford!! They had carburetors with jets and distributers you could adjust but when you made the adjustment you had to wait a minute for the adjustment to kick in. Here's an analogy more up to date - think of adjusting your shower. You have to wait a minute for the hot water to kick in.

 

[Mac Smith]

In smooth waters, I remove the twist in light airs for the use of the vang on with relaxed outhaul, and 3 of 4 tails flying, and boom off center to lee.
In swells, the twist is my friend, in light winds and more.
In heavy winds, the twist is my friend also for spilling air not used, instead of dropping in a reef.