Two-Boat Tuning - SailNet Community
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Two-Boat Tuning

The object behind two-boat tuning is to learn as much as possible about the way you're sailing your boat, and how you can improve that. Note the difference in outhaul tension from one boat to another above.
One of the ways in which top sailors and teams seek to get an advantage over their competitors is by spending time speed testing and tuning against another nearly identical boat. Youíve probably read about sail testing among Americaís Cup campaigns where the boats simply line up and sail against each other in straight lines for hours. Thatís the formal, organized approach to two-boat tuning, but it can also be conducted in a more casual manner, for instance when one-design boats get together 20 minutes before the start of a race to judge their relative boat speed. No matter what approach you take, two-boat tuning can teach you a lot regarding your boat and your teamís performance on the water. And the only thing limiting what you get out of this kind of research is the time and energy youíre willing to put into it. Hereís an overview regarding what you need to know in order to take either approach.

Formal Sessions    Dedicating separate practice time to the goal of getting faster is good use of your timeóthat is if your practice session is set up and conducted in the correct way. If it is not, it can turn into a waste of your time with little to nothing learned. The most important thing to know about two-boat tuning is that you have to minimize all the variables between the boats so what you learn regarding differences in performance can be understood and quantified. You donít want one boat using its racing sails and the other using its practice sails.

In order to make the best use of your time youíll need to make the following preparations:

  • Get a team to sail against that has similar goals as yours. Usually this will be a competitor, but occasionally you may be able to find a good sailor and get access to a boat for them to sail against you. If possible you want to practice against someone sailing with equipment that theyíre accustomed to. This will increase the chances that they will be able to go full speed all the time. You also want to make sure it is someone you have a good relationship with and who will be honest regarding boat speed and heading information. Itís critical that there be open sharing of information sharing between the boats.

    Two-boat tuning is a fundamental tool for Olympic class sailors because it can be an efficient way to learn about sailing technique and equipment.

  • Both boats need to know the details of how their rigs are tuned prior to the session and what sails they will use. By knowing where your rig tune is prior to the session, you are better prepared to make changes, and more importantly, understand the result of those changes. The boats need to share some or all of this information so that everyone knows what the starting point is. Also, make sure both boats have clean bottoms and dry bilges, etc.

  • Ideally, you can arrange to have someone who knows something about your boats observe from a motor boat, and even better, have that person take pictures or video and make notes. This is not critical, but if possible this can really enhance what you learn during the session.
  • Have radios or some other means for easy communication between the boats.

Once you are ready to go, with the equipment set up as identically as possible and both boats in racing shape, have a discussion with everyone involved to explain what you are trying to accomplish. One boat may be having trouble pointing, the other may be having problems accelerating in waves. Make sure both boats know what the other needs to get out of the session. In a good session, both teams learn something about their weaknesses, and each will want to come back and practice again. If you go into a two-boat tuning session looking only to achieve your own goals and you ignore helping the other team, you will learn less yourself and will develop the reputation of being a bad boat to tune against.

Once you get out on the water have both boats sail together in a straight line upwind to get warmed up. Before you work on anything else, the initial goal is trying to get the boats going roughly the same speed, which means putting the crew weight in roughly the same position on both boats and trimming the sails in a nearly identical manner. If one boat is clearly faster, that boat should then keep their trim and tune static while the other boat makes changes to catch up. That means making sail-trim adjustments as well as weight adjustments.

It's extremely important to adjust just one element of your sail trim, rig tune, or sailing technique at a time and see what the result is relative to the other boat before making another change.
Once the slower boat has caught up and is moving at the same speed, alternate spending time as the static boat with the other boat making changes to go faster. Then once the boats are going the same speed, it should be pretty obvious whether a change has made you faster or slower. If you can get faster, then after a few minutes you should shift and become the static boat and let the other team make some changes. There should always be one boat that is the constant in all of this experimenting. And itís important to only make one change at a time so that you can quantify the outcome in terms of gains or losses against the other boat. If you alter the sail trim, and move the crew weight around at the same time, how will you know which change accounts for the difference in performance? Ideally this should lead to both boats getting faster over the course of the session.

When lining up to speed tune, make sure the boats are evenóbow-to-bow and about three or four lengths apart. If one boat always lines up with its bow forward and to leeward they will probably pinch off the windward boat most of the time and you wonít end up learning much. And if the boats are too far apart, you may end up sailing in different winds and again not learn much.

Once you get going, itís important that you spend at least 10 minutes going in a straight line. This will allow you to sail through any puffs or lulls and the gains from the conditions should average out over a longer period of time. If one boat gets a clear advantage quickly, that boat should slow up so that the two boats can line up again and start over. Donít spend a lot of time sailing along when one of the boats has clearly gained and is giving the other boat bad air. There is little value in that.

"Donít spend a lot of time sailing along when one of the boats has clearly gained and is giving the other boat bad air. There is little value in that."

Itís also important that both boats switch sides and each one takes a turn being the weathermost boat on both tacks. You may find that on the day you are practicing, the boat on the left, for example, usually gains because the puffs are coming from that side. So switch things up to ensure that you really know what is going on. Here are some additional prescriptions to ensure that you get the most out of your time spent tuning with two boats:

  • Keep the crew in racing trim, with everyone hiking at the right times. If one boat has crew off the rail and the other doesnít, you wonít learn much.
  • Have someone on each boat be responsible for watching the other boat full-time. Pay attention to how they are trimming sails and where the crew weight is. This person should frequently call out how you are doing relative to the other boat. Try to keep the language simple. All comments should be about your boat, rather than the other one, and use simple, clear language such as "higher and slower right now," "speed and height are even," "even height and faster," etc.
  • As you should in any practice session, take a few breaks to keep your mind fresh, it is really easy to get zoned out when tuning. It can also be boring, particularly for the crew on the rail, so try to keep it fresh and fun.
  • Take the time afterwards to write down what you think you've learned.

These principles apply to downwind tuning as well. Most often racers spend their time tuning upwind and forget about what might be learned downwind. There are gains to be made by focusing on both. Typically, if you are planning to be out for a long time, go upwind for a while, and then head home while sailing downwind.

It happens infrequently, but even Open 60s like those above will occasionally line up to see who has the jets. Of course these custom boats don't lend themselves to informative comparisons bescause they are so different from one boat to another.
Casual Pre-Race Tuning   OK, letís assume that your life is so busy you canít allot time for a practice session. If thatís the case, there are still plenty of opportunities for you do some two-boat tuning and learn a fair bit. To do this, all you need to do is get out to the racecourse early on a racing dayówith a tuning partner. Again, your partner should be someone you trust, and ideally someone you think has good boat speed. The advantage of these casual sessions is that tuning on race day usually ensures that your partner will be in racing trim, with good sails, a clean bottom, and the boatís regular crew. So chances are that boat will be sailing at optimum speed, which is good for you.

Given the circumstances, you may not have as much open discussion about setups prior to getting out on the water, but once youíre out there, get together right away and start sailing upwind. The same procedures for lining up still apply: get your bows even, about three lengths apart, and switch sides occasionally.

Among your crew, you should use this tune up as an opportunity to get into race mode, and try to sail as fast as you can. If one boat appears to have a clear advantage, try to figure out why. Have someone on your crew who has a good eye look at the setup on the other boatótheir trim, their weight placement, etc. How hard are they sheeting? Do they have full or partial flow on their top telltales? Where are their jib leads? How tight are their halyards? Where is their main traveler? How much are they heeled? How hard is the crew hiking? The answers to questions like these will tell you something definitive about any differences between the boats. Even if you are the boat with the speed advantage, it is important to understand why you have that advantage, so pay attention to the other boat and analyze.

"Don't forget, a pre-race tuning session is also a good time to collect information regarding the racecourse."
A pre-race tuning session is also a good time to collect information regarding the racecourse. If the boat on the right usually gains this will tell you something about the conditions. So have at least one crew looking at the racecourse all the time, watching the other boats while they practice, looking at the water, the clouds, etc. Then once your session is over and you are sailing back to the starting line, get the crew together and discuss what youíve learned about your performance and the racecourse.

Of course, throughout your tuning session youíll want to keep an eye on your watch and not get too far away from the starting line. And be sure to leave some time for downwind tuning and boat-handling practice. Because of that, you'll want to make sure that all of this happens early enough so that your crew has a few moments to get set up for the race and catch their breath once youíre back at the line before the guns start going off.

Regardless of whether you conduct your tuning on a dedicated day or simply before a race gets going, you should attempt to make the best use of your time. Keep your eyes open to what is going on around you and the changes being made on each boat, and get in the habit of writing down everything you learn. Attention to detail is the cornerstone of two-boat tuning, and it will make you a faster, better sailor over time.

Suggested Reading:

Team Building Basics by Betsy Alison

On the Road at the CISA Racing Clinic by Zack Leonard

Lessons Learned in Error by Dan Dickison

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Dean Brenner is offline  
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