How To Practice Sail trim

May 17, 2004
2,099
Other Catalina 30 Tucson, AZ
A short time ago I was talking to a Colorado friend, who's a Catalina 25 trailer sailor. I meet him a few years ago at a trailer sailor convention in Lake Havasu, AZ. I was conducting a sail trim seminar for over 150 participants. These trailer sailors love their boats and really want to get as much efficiency out of them as they can. They're rabid about sail trim!! Anyway, a blizzard was raging outside his home but he was comfy in front of his fireplace enjoying a whiskey toddy -- or two!! He was looking out at his boat as it was being covered with more & more snow -- I almost think he wanted to bring it inside with him!!

At one point in the conversation he said that as soon as he puts his boat in the water, the first thing he wants to do is improve his sail trim technique. He asked me what single sail trim control for the main and jib he should work on first. I told him ALL OF THEM AT THE SAME TIME and then went on to explain WHY I think that's the only way to proceed. This subject has come up a couple of times and I've answered it different ways but it all boils down to this. Think of a golfer at the driving range working only on his grip. What about his stance, how the club face addresses the ball, his back swing and other elements that are involved with hitting a golf ball. It doesn't make any difference what sport a person is participating in (hitting a tennis ball or baseball, shooting a basketball etc) there is a a set procedure a person has to go through to attain efficiency and consistency.

Frequently, sailors tell me they want to work on the traveler or jib fairleads. Here's the problem as I see it. There are 8 primary controls for the main and 6 for the jib. For a given point of sail and wind condition there's a particular setting for each control. If a sailor doesn't get it right it's similar to shifting a sports car into 2nd gear and flooring the accelerator and at the same time applying the emergency brake. In other words, if ALL the control are not in unison they work against each other.

The trick to learning to do anything is to figure out what happens when you push, pull or hit something. That is my advise to beginner sailors (in the frame work of my personal experience, trying to master the intricacies of sail trim) - figure out what is happening when you do something and don't over think it,Over thinking anything, in my opinion, is the kiss of death. Everyone hears a different drummer but once I figured out WHAT the sail controls were actually adjusting, the settings that gave me the best efficiency for each point of sail and wind condition were easy to determine. There was lot of stuff to remember so I noted it all. I even figured out where best to place the crew in each situation!! I didn't know it at the time but those notes became the SAIL TRIM CHART and it's companion THE SAIL TRIM USERS GUIDE.

I'm sure some of your sailing friends have asked most of you the same question. What advise did you give them??
 
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Feb 17, 2006
5,274
Lancer 27PS MCB Camp Pendleton KF6BL
Very nice, Don...

For me it is the same advice I give myself. I also tend to overthink and the results is a stalled boat. My first and foremost goal is to get the boat driving. With that, I concentrate of setting the main. Not until that is done do I then concentrate on the headsail. Setting the main for drive is basically easy. Setting it for efficiency takes a little time for me (hence the overthink). I know that the two sails interact so fiddling with one will affect the other.

My biggest problem is light wind conditions. I can never seem to get the boat moving. LOL
 
Sep 20, 2014
1,320
Rob Legg RL24 Chain O'Lakes
I advise a Yard Sail. If you don't know what each line is going to do to the sail shape, then you have no idea even where to start. Once you understand how to change the sail shape, then you can apply it out on the water and see how the boat responds. The second is that your sail draft is your transmission. Deeper draft is downshifting to a a lower gear. Shallow draft will bring more speed if you have enough wind power to convert it to speed.
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
The first question I want to know about sail trim, where maximising efficiency is the goal, is how will I know when I've got it right? I can go out and set my course and trim my sails and look out and see that I'm moving thru the water. I can look up and see that my sail peak is at the top and my downhaul is tight by the nice smooth luff line. I can sheet the sails in so they stop luffing and try to tighten the outhaul on a close reach or loosen it for a broad reach. I can vang the boom and move the traveler cars. I can even tighten or loosen the battens and bend the mast to affect the sail shape, but how will a I know I have it just right?
There has to be something to compare it to. I have to go out there and measure the conditions and my speed. Even then, conditions are so rarely the same from one hour to the next. It would be most helpful to have a second boat to compare your performance to. It would be helpful to get the outboard set of eyes to tell you how you look, when you move, to maintain a steady vector under near similar conditions to measure your self against. In this way, you get a better idea of how your doing

- Will (Dragonfly)
 
Oct 22, 2014
20,995
CAL 35 Cruiser #21 moored EVERETT WA
Will you will need to establish metrics.
  1. Set and trim the sails.
  2. Record the trim settings
  3. Record the conditions
  4. Identify and record the speed
  5. Adjust the trim
  6. Repeat 2, 3 and 4
You will quickly establish the trim for conditions model. Not that it will be as much fun as just buzzing about on the water or jumping on the boat and heading for your favorite spot or pub.

Another way is to go out and race other boats. It has the air of Darwinism but is quite effective. Identifying who is the fastest usually means the best Sail trim.
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
As you know, I grew up sailing. At a very early age, my father taught me to let the sail out until it just starts to luff, then sheet it back in to where it just stops luffing. He taught me about apparent wind moving forward as you pickup speed. Sheeting tighter as the apparent winds moves forward with your acceleration.
Imagine the frustration in an 8 year old boy when he goes of to Summer camp where they have sailboats on a lake and his sailing buddies just want to haul the sail in tight to make the boat go 'faster' because heeling angle equals speed in their minds.
Imagine their frustration when I wouldn't do it. I must have seemed like the oldest fogey it as possible for an 8 year old to be. :frown:
The fact was, the camp wasn't about to let us out on the lake if there was enough wind to really get going anyhow. They had a small fleet of Sunfish and these little trimirands that held 2 kids. No one went out alone, except me and one other kid with experience like mine.

- Will (Dragonfly)
 
Oct 19, 2017
7,733
O'Day 19 Littleton, NH
You'll know by the feel of the helm, the heel of the boat and the numbers on the speedo.
That is true!?! But can you explain it?
Not the kind of thing you go out and practice. That's more the kind of sense you develop over a great deal of time.

- Will (Dragonfly)
 
Sep 20, 2014
1,320
Rob Legg RL24 Chain O'Lakes
You make one adjustment at a time, and see if you speed up or slow down. Recording conditions to me seems a bit overkill. You need to sense conditions by sea state and just overall feel. That is usually fine for the wind, but not so much for small changes in boat speed. Boat speed should be measured, although sometimes you can just tell. I will probably always remember the time I was sailing along "just fine" and dropped the main halyard about 2 inches and the boat just took off.

One other general guide I've started to use is watching the telltails on the leeward side of the sail. What I have tried to do is pull the sail in to find the point where the telltails start to drop, and then let it out a little beyond that point. Knowing that most of the force that moves the boat comes from removing air on the leeward side of the sail, I assume I want to be right at the point where the wind still solidly tracks the leeward side.
 
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Jan 1, 2006
7,040
Slickcraft 26 Sailfish
Most of us are probably chronically over trimmed in anything except a beat. Maybe in light air upwind too. I think the notion that heel is fast is probably the reason. My advice for beginners? "Let de bot walk, Mon"
 
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Oct 19, 2017
7,733
O'Day 19 Littleton, NH
I was sailing along "just fine" and dropped the main halyard about 2 inches and the boat just took off.
See, that's the point I'm trying to get at. How did you come to think of dropping the main? That's not a obvious adjustment to make. How do you know, after that, that you were at maximum efficiency? All we can know is what has worked best for us relative to past performance or someone else's performance. We assume best practice based on the process of elimination. Sailors who race have the best handle on performance sailing. But, as I've commented above, heeling hard gives the impression of speed, even when it isn't the most efficient. So, simply going out and practicing sail trim without a frame of reference doesn't seem like a great approach.
I'm not saying it doesn't help and high performance can't be reached, just that there are more efficient ways to gauge and improve, beginning with the brain and some creative thought.

- Will (Dragonfly)
 
Sep 20, 2014
1,320
Rob Legg RL24 Chain O'Lakes
I think I remember Jackdaw saying its pretty common to over tighten everything. So maybe a better approach is starting with everything loose and tighten till the boat stops accelerating. What you tighten should be based on how the telltails fly. If the upper leeward telltails aren't flying, then you probably need less vang or move the main car windward. My experience has been that it seems like the outhaul adjusts the lower portion of the sail. The Cunningham adjusts the middle belly, and the vang or the main sheet traveler adjusts the upper part of the sail or twist. My main is a pinhead, so there isn't much draft to adjust up high anyway. The main halyard seems to interact with the Cunningham and seems to affect the hook. Too much halyard, and the draft moves aft, and the leach tends to hook. This is just what I have found with my 20+ year old main sail. Maybe new sails would act differently, I don't know. It is only this past season that I have really tried to work on sail shape, so I'm only stating what I have found so far. As far as what moves what, I figured that out in my last Yard Sail.
Back to Don's point, all adjustments interact, so you make small adjustments at a time, to bring the sail into shape.
 
May 17, 2004
2,099
Other Catalina 30 Tucson, AZ
I advise a Yard Sail. If you don't know what each line is going to do to the sail shape, then you have no idea even where to start.
Dave: Absolutely, on both points. On the yard sail -- when I decided to get back into sailing years ago, the first boat I purchased was a Mac 22 on Lake Havasu, AZ where we had a second home. Lake Havasu is a poor place to sail because it only blows two ways -- zero knots or 90 knots and nothing in between. I quickly realized I needed lessons but thought I could figure sail trim out by myself. One day I hoisted the main and jib in the driveway and a heavy gust of wind came out of nowhere and I sailed the boat into my fence!!

My problem with learning sail trim was no different than any beginner sailor worldwide -- I had no idea where to start. Also, the answers I received from sailing friends confused the hell out of me. I had no idea what they were talking about and later on I realized they didn't know either!! When I started this forum many years ago, I created it to be centered around beginner sailors because I didn't want them to go through what I did to learn how to sail a silly sailboat. I try to keep my explanation as simple as possible and in plain English. Sometimes they don't know how to express the question but reflecting on my "learning the hard way experience" I know what they're trying to ask.

Learning sail trim is like buying a tool, camera, computer etc without a instruction manual and then starting to mess with it to figure out how it works. It's backwards. Again, once I figured out what all the sail trim controls for the main & jib are adjusting , which is draft depth, draft position, twist & angle of attack, sail trim became simple because I had the basics.
 
Sep 20, 2014
1,320
Rob Legg RL24 Chain O'Lakes
If you want to simplify it, there are only two sail adjustments. Angle of attack, and draft. All the different lines and adjustments are only there to get the draft and angle of attack "uniform" throughout the entire height of the sail. I use the word "uniform" relative to the wind variability form the top to the bottom of the sail.

I heard an interview with a stunt coordinator. They were asking the coordinator how they calculated the angle of a jump and speed required to perform a specific stunt. Did they use computer software and simulate the stunt to make sure that had everything right. The answer was NO. The guy stated the human brain is an amazing computer that can just look at something and know what is necessary to perform the stunt. If course that comes from many years of doing stunts and just learning what works by experience. So the same with sailing. Yes, it takes time to develop instinct, but it still is just how much draft does your specific boat need for a given amount of wind. That you learn be trying.
 
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Joe

.
Jun 1, 2004
7,999
Catalina 27 Mission Bay, San Diego
If you want to simplify it, there are only two sail adjustments. Angle of attack, and draft. ..........
heh, heh..... I'm sure you'll get a challenge on that statement..... especially since it's posted in Don's thread.
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
I hesitated to respond to this, because there is no simple answer. If there was was one thing that everyone should work on first, everyone would be expert, and clearly that's not the case. But here are some thoughts.

Because there are so many sail controls, you have to prioritise them. The outhaul is important of course, but we adjust ours 1/10 as much as the traveler and sheet. Create your priority list. Focus on the primary controls. Monitor the secondary and tertiary.

A good and full set of tell-tails is fundamental. Top to bottom both sails. Trim and steering on the jib luff. Leach on both.

Always remember that the headsail and main work TOGETHER as a single wing. 1+1=3. You have to trim them together, and a change to one probably means a change to the other.

Good sail trim is A FULL TIME JOB.

Always know what mode the driver is in. For going upwind, is he in pinch/feather mode, VMG, or foot mode? Is she fetching and wants you to trim to her?

Learn how to shift gears. Changes in conditions (True Wind Speed) will require wholesale changes in trim. Know what trim will be required for a +4 or -4 knots of true wind, and what that will look like on the water.

Practice in marginal conditions. OK, you're beam reaching in 12 knots true and killing it. Guess what? EVERYONE kills it in those conditions. Practice in conditions you would normally start your motor. THAT makes you better at trim.
 
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May 17, 2004
2,099
Other Catalina 30 Tucson, AZ
heh, heh..... I'm sure you'll get a challenge on that statement..... especially since it's posted in Don's thread.
Dave: I'm all for simplification but there are 2 parts to draft - draft depth & draft position. They are 2 different things and separate controls are used to adjust those 2 element. The 4th element is twist and that's why the boom vang was invented.

Joe from San Diego made a comment about the "feel of the helm".That struck a chord with me because it's a beautiful thing when it happens to you for the first time. I can't describe it but it's like the boat talked to me. I felt it in my feet -- the balance was perfect for boat speed and wind conditions. Then the conditions changed and I couldn't get it back again that day. But as I got better with sail trim I started experiencing it more and more. It's like driving a sports car smoothly and floating through the turns and not fighting the car. The first time it happened I was alone (just me and my Cocker Spaniel) so I had no one to share the moment with. Later, I tried to explain it to my wife but couldn't put it into words - still can't but when Joe mentioned it the feeling came back to me.
 
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