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bruceyp 10-04-2007 02:29 PM

The finer points of sail trim
Though I have been sailing for a good part of my life, I have avoided racing except to crew for friends. But on a lark, I entered my boat in a race and got my tail kicked. That in itself wasn't bad, I didn't expect to do that well. But I realized that there are a few things on my boat that I have never really learned to use, and I am, after all, intereseted in getting the most boat speed from my boat. They are the vang, the topping lift, and the traveller. When do I trim and when do I ease? (I'm sure this is going to be a loooong thread, but I'm sure I'm not the only one who will benefit from this info).
Bruceyp of the Hannah Lee

nolatom 10-04-2007 03:17 PM

Vang, topping lift, traveler.

Well, you want the topping lift slack, so it doesn't fight your mainsheet when trimming close-hauled. Otherwise, forget the topping lift (except maybe in zero air if the mainsail leech is too tight).

Vang. Use it downwind, keep fairly tight to keep the boom down and avoid too much twist in the sail. Upwind, if you have one, you use the....

Traveler. If windy, ease it to lee a little, or a lot. Once the mainsheet is close-hauled, it becomes your up/down leech loosener/tightener, which helps you flatten or make fuller, the Main. The traveler then is your in/out control (like a mainsheet, but with a narrower range. Use leech telltales to see how the leech tension and twist are, you want them to flow aft.

Way more to say about all the above, but many web sites say it better, and longer.

You didn't mention halyard tension (or cunningham, or downhaul if a sliding gooseneck), outhaul, or backstay. Generally tightening them flattens the sail (for windy conditions, or for smoother water), loosening makes it baggier for lighter air or choppy sea (like a lower gear on a car or bike).

then there's the jib. same deal re halyard tension, and fore/aft side/side angle for the jibsheet leads.

Much depends on the boat, the sails, and the conditions. Racing's boatspeed first, then clear air above all, tack on headers, stay on lifts, don't be over at the start, don't pinch too much, don't foot too much, mark you ballot carefully, and keep the ball low...;-)

Enjoy racing. Best sailing school there is. Eventually someone else's ass will be getting kicked, you're up to mid-fleet, and liking it a lot more.

Okay, this will get it started? others chime in with better pointers than me.

poltergeist 10-04-2007 03:21 PM

What kind of boat do you sail?


JohnRPollard 10-04-2007 03:33 PM


That's great that you're giving racing a try. It's a good way to improve sailing skills. It can be hard to do that in a vacuum abord your own boat, unless you have someone more experienced aboard. So you might want to consider signing on as crew aboard one of those winning boats to learn a few tricks of the trade.

As to your questions, I have to say I am somewhat puzzled at your suggestion that you don't use your topping lift? [I assume you are refering to the boom topping lift, not the spinnaker pole's?] Unless by that you mean that you don't adjust it after you have raised the mainsail and then completely eased it? As long as you are easing it after raising the main, you shouldn't touch it again until it's time to drop the mainsail. It is not normally used for sail trim.

As for the traveller: Very generally speaking, you are going to bring the traveller up toward the windward side of the boat for upwind sailing, and ease it down to leeward when sailing off the wind. Going upwind, you would never want to raise it so high to windward that the boom crosses over the fore-and-aft centerline of the deck to the windward side of the boat. Depending on the wind conditions, you may need to "play" the traveller quite a bit as you're sailing upwind. That would usually be in heavier air, when you would leave the mainsheet set at the appropriate trim and just drop the traveller down during puffs to spill some of the breeze.

Vang: It primarily helps to hold the boom down when the main is fully eased off the wind, because at those sheeting angles the mainsheet is no longer holding the boom down. As a very general rule, sail with a moderate amount of tension on it, rather than leaving it loose.

This could be a very long thread, but there are many helpful books on sailtrim that you might consider. I'm drawing a blank on titles but others might toss a few out.

tomaz_423 10-04-2007 03:55 PM

Yes, there are many books, but nolatom almost covered all the basics in few lines.
There are other important controls as well (like back stay tension), ...

Racing with others would improve your skills very fast.

tenuki 10-04-2007 04:51 PM

hmn, vang and traveller... I thought until you knew how to use those you weren't allowed off the lasers, what you doin on a big boat?.... ;)

IMHO finer points would be outhaul, cunningham, backstay, leech lines, barber hauler, rig tune, telltail break points for different conditions and points of sail, twist, etc. I think I actually adjust my traveller and boom vang more often than my mainsheet.

tenuki 10-04-2007 08:39 PM

And now for a more helpful post. :) This is from the bizzarro AFOC tenuki school of sail trim, so be prepared for a bit of strangeness and undoubtedly some inaccuracies.

Sail trim for the blind, deaf and dumb, literally:

Hold the tiller in your hand, strike a steady course to windward take a couple of deep breaths, feel the movement of the boat through your seat, then close your eyes. That's right. Feel the tiller in your hand. How does it feel?

- inert, ie totally neutral. ok, you need at least some weather helm, get more sail power aft. power up the main and depower the jib/genny.

- lee helm - ok, problems here, you need to move sail power aft now! same sorts of stuff as neutral helm but more drastic

- strong weather helm, boat is fighting you - time to move sail power forward! depower main now, and maybe power up genny if appropriate.

- strong lee helm - ok, you must reef or drop that jib/jenny now! oops, you forgot to raise the main, do that now.

- light weather helm, boat feels responsive and in control - smile you are in the fast lane. Now open your eyes, you're gonna hit that DUCK!!

other points of sail have their own special subtly, but they can all be deduced with your eyes closed. start there, a balanced boat is a happy and fast boat. the balance shows at the tiller.


Wacked notes on 'sail power'. (this is just to set down a point of departure for the conversation - kibitzers join in!) for example: increasing sailpower in the genny moves the total sail power foward. here are the effects of the control on the sail power of the sail they control.

Main (aft power)
outhaul ( tightening - | ease + )
sheet ( tightening + | ease - )
traveler ( to windward + | to leeward - )
cunningham ( tighten - | ease + )
vang ( tighten - | ease + )
reef ( in - | out + )
halyard ( tighten - | ease + | drop -- | raise ++ )

Genny (fore power)
sheet ( tighten + | ease - )
reef ( in - | out + )
halyard ( tighten - | ease + | drop -- | raise ++ )

Crew weight effect on balance

goes in direction opposite of the movement of power, ie
you need to move sail power aft, move crew weight fore.


So, which control do you use once you figure out what you need to do to balance? Easiest way is probably to look at the sail shape, the telltales, etc. To really understand how boat balance works in relationship to sail trim you need to spend serious time sailing without using the tiller, either lash it down or let it swing free. everything starts and ends at the tiller IMHO.

Hope that is useful or at least starts a good argument!

blt2ski 10-05-2007 02:49 AM

So this is what I get to look forward too on my boat saturday, tenuki wth his sail control workshop. Should be fun in 20 knot winds!


tenuki 10-05-2007 03:19 AM

hahah, I'm just rail meat. I'll be following instructions and learning from you mr laser racer. :D

Ya, I was looking at the forcast looks like a screamer fun race is in order! Up to 25 knots, now that will be fun. We're still flying the spinnaker, right?

blt2ski 10-05-2007 09:48 AM

Oh yeah, spinny is going up. First leg no less, not sure about second, depends upon wind speed, last leg is a beat, with maybe two tacks, altho if the wind is out of the SW vs predicted S, then it will be one tack. First leg would be a reach, 2nd a quick spinny run. If SE, the definetly a run first leg straight down wind, reach second leg, third a couple of tacks home. A rue south wind would be the most spinny potetial useage, and best for my asymetric!

We are going to try and meet at the dock jut before 8am, sheryl will be at skippers meeting, kids and I will be setting lines etc up. tart should be 10:05 or 10:10 depending upon number of boats and are placement. Slow boats first, then faster rated boats later. I know we will not be fist out, that will be NFS, then slow FS, probably us with a 203 rating! I'll ty to phone you tonight from home, cell is under boat as of two nights ago when bending over to tighten up the shrouds from adjusting them!grrrrrrrrrrrrrr............


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