Tuning advice to improve your windsurfing
By Tom Ingram (April, 2008) updated and edited by Dan Weiss (October, 2013)
This article is intended to provide a basic guide for intermediate level sailors to racing the Kona One, as well as to provide some tuning advice for more experienced sailors who may not be as familiar with racing the Kona.
Skills needed to race a Kona One
To race a Kona, a windsurfer needs to be able to (a) tack and (b) jibe. That’s it. The Kona is an easy board to sail, tack and jibe, and one does not need to be a World Champion to get it around the course. In winds below 15 knots, someone with sailboat racing experience and modest windsurfing ability could do very well. Once winds allow for full planing conditions, sailing Kona is similar to sailing a shortboard – it takes some practice but is relatively easy for a windsurfer.
Racing Kona is not about supreme technical ability, but about having good starts and sailing tactics to get around the course first. Because it tacks very quickly, the sailor can use small wind shifts to his advantage rather than sailing through them and “banging the corner” (one tack) to get to the upwind mark. Racing Konas in light and moderate air is more akin to racing sailboat dinghies like the Laser or 420 than to racing Formula class boards and rigs. Though you may not be planing, your more experienced windsurfing buddies will be a few boardlengths away, instead of already being back on shore eating lunch!
Board and sail setup
While Kona racing is still in its infancy, and the ultimate performance out of the one design board and sail has probably yet to be fully realized, the following tuning tips are offered as a suggestion as to where to begin with the board. The Kona One has several one-design sail sizes to equalize the performance of the different weight categories.
The 6.6 square meter size is for sailors under 65 kg, the 7.4 is for sailors from 65 to under 75 kg, the 8.2 is for sailors from 75kg to under 85kg, the 9.0 is for sailors 85kg to under 98 kg and the 9.8 is for sailors 98 kg and above. These sizes are pretty evenly matched in performance, with possibly a slight edge to sailors at the lower limit of each size, like the proverbial 66 kg or 86 kg sailor.
Good sail tuning and tactics on small to medium sized courses (like finishing in under 30 minutes) over several races in a regatta usually overcome these slight performance differences, certainly more so than any one design windsurfer has done in the past.
The sails handle a wide range of wind speeds with proper tuning. Tuning these sails correctly is very important for getting maximum performance, particularly in light air.
If wind conditions change during racing, it is easy to change the sail’s downhaul and outhaul settings and the mast track setting while out on the course between races. Just separate the rig from the mast base while sitting on the board, but make sure not to let go of the sail as it will sink!
Light air (not planing at any angle of sail, or from about 4 knots to 12 knots)
The mast track should be set in the forward 1/5 of the mast track in light air to maximize the length of the waterline. In sub-planing conditions, waterline length (the length of a hull in the water from front to back) determines the maximum speed of the hull. Having the mast track towards the front helps keep the nose down low, closer to the water. Experienced racers are currently running their mast bases so that the center of the universal joint is about 5-10cm back from the most forward position, or just far enough back to avoid the nose pearling (digging into the waves) at any point of sail.
Absolute minimum downhaul should be used, like just enough to pull the wrinkles out of the luff of the sail. The batten below the boom should not be rotating easily – if set correctly, you will have to kick it or move it with your hands after each tack in lighter winds. This is not difficult. The leech (trailing edge of the sail above the boom) should be tight, so that it does not twist (or twists as little as possible) when filled with wind. This setting should be used in light air until such time as the sail becomes unstable or the sailor begins to have to sheet out (ease the sail)
The sail’s ability to generate lift is highly dependent upon having adequate batten tension. The bottom four battens are particularly critical. There should be enough tension in these to give the sail a pronounced curve even when there is no outhaul or downhaul applied. Far more batten tension than than normally used in most freeride or wave sails, but it works and is fast. It is normal to have the monofilm stretched tight around the bottom three battens. Failure to have adequate batten tension will result in your not being able to point as high or go as fast as the rest of the fleet. It will cause the sail to be less stable in moderate to high winds and lead to feelings of inferiority and frustration on the race course. Basically, in light to moderate winds, you are aiming for as much tension as the sail can stand in the bottom four battens without damaging the sail. After tensioning the third batten down from the top, make sure that it can still rotate – you may have to back off the tension a little bit to allow it to do so. In the top two battens, tension those just enough to pull the wrinkles out. In higher winds, the tension in the third and fourth battens from the top can be eased slightly to flatten the profile of the sail.
For light air, the sail should be touching the boom from the clew forward to just behind the rearmost harness line. In other words, it should be pretty baggy. For the 7.4, that equates to an outhaul setting of about 199 cm, though you would normally set the boom so that you could pull in the outhaul a few cm (approximately 202) in case the wind picks up. The lower clew grommet should be used. An adjustable outhaul is highly recommended.
For sailing upwind, the centerboard should be all the way down. For reaching, it should probably be all the way down, though if the board starts wanting to rail up, then it may make sense to retract it slightly. For sailing straight downwind, it should be all the way up.
For sailing upwind, position your feet so that the board is heeled (railed) to leeward (away from the wind). It is important to maintain that heel angle constantly, and not jostle about. Be a cat, not Bigfoot, on the board. Bouncing around disrupts forward momentum. It is normal for the board to crab (slip) a little to leeward as you are sailing upwind. Finding the perfect balance between sailing fast and having a good angle to windward takes practice. For occasional racers, the best thing to do is to look around at the other sailors and see how they are doing compared to you. Keep the rig vertical, not hanging to leeward – this means your arms may need to bend slightly. The exceptionally good racers even try to hang down from the booms to get out of the airflow around the sail.
For racing in light air, move the front footstraps to the inside positions so they do not drag as much through the water when you are heeling the board. For recreational sailing, it does not matter where they are since they will not be used.
Getting a clean start, with clean air (no turbulence coming off of other people’s sails), is critical to doing well. Sailing fast in little wind requires a great deal of concentration – daydreaming for a few seconds or looking at the birds can lose boatlengths. Using the small wavelets or motorboat wakes to initiate surfing downwind can make a big difference. On a straight downwind leg, make sure the nose is close to the water at all times, just high enough to not pearl (submerge) constantly. If the nose pearls 2-3 times during the downwind leg, you’re probably pretty close to having it right. Resist the urge to sheet out slightly when you get a puff of wind.
Moderate air (planing on the reaches, possibly on the downwind leg)
The mast track should generally be about the same as for light air – maybe a cm or two back if there is chop that causes the nose to dig into the waves, but otherwise, it should be well forward.
No major changes need to be made to the sail from the light wind setting. The sail should still be bagged out pretty good and the leech tight. For the 7.4, this equates to a total luff length of about 467. Only when you start to have control issues or are fighting the sail should you downhaul the sail a few cm to twist off the top of the sail. Err on the side of having more power, not less.
No major change from the light air setting, maybe a cm or two more so that the camber of the sail is about the same as it was in light air. Your boom should be set about 2cm longer than the light air setting.
Same as for light air. Resist the urge to bear off onto a planing reach on the upwind leg. It is faster to point high with the centerboard all the way down.
If you are racing and only occasionally planing, you may want to leave the forward straps on the inside settings, especially if the water is smooth enough that you do not need to really use them. That way, the forward part of the front straps is not dragging through the water when heeling the board going upwind. For recreational sailing, the straps should be in the outboard position – sailing with the feet further outboard is definitely faster. Even if the front strap is inboard while racing, position your front foot out closer to the rail when planing. Most of the heavier sailors put the straps in the rearmost position, though medium weight sailors may keep them one forward.
In moderate air conditions, where it may be possible to plane when reaching or on a slight broad reach, it is still generally fastest to sail upwind legs of a course with the centerboard all the way down. On a longer reach in marginal planing conditions, it may pay to point high at the beginning of the reach in order to have a good planing angle for the rest of the leg. On downwind legs, it can be fastest to sail straight downwind rather than sailing broad reaches and jibing, but the threshold for when sailing broad reaches pays off is very dependent on wind strength and the consistency of the breeze.
In heavy air, like 20 knots plus, the Kona can plane all the way around the course. If there are lulls in the course, there may be periods where sailing with the centerboard down going upwind is faster than trying to plane upwind. To plane upwind using the current sail sizes and fin, it needs to be very windy, with lulls no less than about 16 knots, to be effective. The sail settings are intended to reduce power and improve control.
There is not a general consensus on what the right mast track position is in heavy air, yet, but setting the track about 1/3 back from the front (or around 10cm back from the front of the track) seems to provide a good balance between being able to sail upwind and plane fast downwind. If the course is primarily reaching or downwind, with very little upwind, then consider placing the mast base 1/2 back or maybe a little further back. Having the track back may help with the maximum reaching and downwind speed and in jibes. Started in 2013, the Kona One’s deck is now printed with nearly exact mast foot positions for every sail size!
For high wind, increase the downhaul. However, if you are used to putting high downhaul tension on your other sails, take it easy – it doesn’t need as much tension due to the relatively shallow luff curve. The upper battens should twist off evenly from the top to boom when the sail is sheeted in. If the maximum twist is occurring around the third batten down, with less twist above and below, then there is too much downhaul. Using the outhaul as the primary means of maintaining control, rather than having extreme downhaul.
The boom (if adjustable) should be set so that you can pull the sail as flat as needed to maintain control in the gusts, and should generally be set on the lower clew grommet. For super high wind, the outhaul setting is about 205-207 on the 7.4 sail. It is possible to pull the sail too flat and lose power, so it is useful to have an adjustable outhaul that you can use to ease the sail out just enough to have the maximum power that can be controlled.
If planing all the way around the course, the centerboard should stay up. However, if you are having to bear off to a reach (90 degrees to the wind) during lulls in order to stay planing while going on the upwind leg, you are probably better off switching to subplaning mode and putting the centerboard all or most of the way down and sailing to windward at a high angle.
For planing conditions, the board should be flat or slightly to leeward.
The footstraps should be in their outboard positions, either all the way back or one forward.
Falling is slow. Wind shifts become less important. You are sailing at such shallow angles to windward that it can be hard to tell where the layline is. If you understand the layline while planing upwind, it may pay off to slow down, put the centerboard down and sail subplaning upwind at a higher angle for the last bit of the windward leg rather than trying to tack two more times and plane the whole way.