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Lessons from SIN Cat Nationals

The 1oth Singapore National Titles gave us our first opportunity to trial the Viper F16 against 3 of the Nacra 20’s, now that they’ve settled in. This report is purely written to give our insights from our platform, some of the ‘experiments’ that we were running over the weekend and has been put down so that those interested will hopefully learn something from it… perhaps!

If you want to read about results go to the Club Report.

Weekend ONE
First of all, we took ‘Sycorax’ out of the boat park only 2 weekends before the Nationals. I tested the diamond wires and they seemed a little “soft” the spreader rake was re-adjusted down to about 30mm and then I wound the diamond wires up super tight. Two hours later we were racing against our ‘old’ Viper (ex-Yeahbaby). So that would provide a reliable bench mark for our performance. Also in that company was Red Rocket Guy’s Nacra 20 crewed by Kelvin Holdt, so we had 2 very reliable bench marks in a race environment that had a decent beat, good wind and a great spinnaker run… All good measuring guages!

The result after a few races, we had a huge pointing advantage over both the other Viper F16 and the N20. Downwind the N20 was too powerful, generally driving deeper angles with more speed. We had a boat speed advantage over the other Viper, probably down to a technique issue more than anything although they were carrying their mast rake in the 3rd hole whereas I never take mine out of the 4th pin hole!

Summary: The big height advantage (a good 5 -6 degrees) could be used to devastating use although I was not particularly happy with the boat speed or acceleration at these high angles!

Weekend TWO.
Catamaran Nationals, 8 races over 2 days, good wind, a fleet of F16’s plus the 3 Nacra 20’s – perfect! Right off the bat,
Experiment 1 – something told me I’d set the diamond wires to tight so I let them off for Race Day to try to keep the same angle of attack but gain more acceleration and top speed!
Experiment 2 – THIS IS CRUCIAL, we sailed the Viper with a different style on Saturday than we did on Sunday!
Experiment 3 – while sailing parallel with a expertly driven N20 we were able to vary the mast rotation and observe the differences of trim/height/attitude/speed…
Experiment 4 – I changed my tacking technique ever so slightly, but it worked REALLY well.
Experiment 5 – I changed the amount of twist in the mainsail downwind.
Experiment 6 – we ran a different amount of outhaul all weekend!

So the nitty gritty
Saturday’s medium air.
We got buried off the start line in race one but found that we could still easily use the pointing advantage to climb out of dirty air. We could still out point all the other teams and once in clear air, the boat speed was back up with better acceleration. But blowing the mainsheet shackle really hampered progress and cost staying with the leaders, falling back into the middle of the pack, fixing it and then getting back up to 4th again. So boat speed and angle were both good.

For the remaining 4 races we sailed the Viper in this ‘high mode’. It felt rather weird to be sailing this high but in most cases it worked so well that we could take ‘inside’ others and still climb to windward of them.

Against the N20’s, 2 of them were carrying more upwind speed but at a lesser angle.
Against the other top Viper (Isdoo) we held a clear pointing advantage although speeds were for the most part very similar.

‘Experiment ONE’, had paid off! (I still think there’s more in there).

‘Experiment TWO’. Different Sailing Style from one day to the next! Why?
While sitting in out ‘high mode’ I had a great view of benchmark boats a few boat lengths to leeward. We could watch them drive hard at lesser angles, as long as we concentrated on the high grove we would surely come out ahead further up the track. On some occasions, they would ‘bust through’ and manage to cross ahead of us on the next tack. This happened most often on port tack when a prevailing header system was in place, so that was to be expected.
On the starboard tack, there was a tidal influence interacting with the foils. At our high angles of attack, our foils would be ‘positive’ to the tidal stream and therefore we’d generally gain an advantage.

We continued in this vein for the remainder of the  upwind legs, just concentrating on sailing in high mode. It takes a great deal of concentration to keep the boat at speed while sailing extremely high and its easy to fall out of this groove!

Overnight I decided I’d drive the Viper differently on Sunday day two, just to see what the difference would be if we sailed “back down to everyone else’s pointing angles”. Of course this is just like footing off 4 degrees, so it was anticipated that boat speed would naturally increase!

Well the difference was quite a lot. On Sunday, ‘sailing lower’ we were able to keep pace with the Nacra 20’s while pulling away from the other F16’s. We found we could easily stay with the leading N20 for the whole beat and on a few occasions, pip them around the top mark. All Sunday, we sailed in this ‘low mode’ until we really needed to climb out of dirty air, then we’d just switch to ‘high mode’ again… NICE!

Experiment 3 – lessons in rotation
Being able to stick right on top of the top N20’s allowed us to get into the next ‘Experiment’ of progressively altering the rotation on a single leg! The N20 is so powerful it tends to hold momentum so it became the ideal performance benchmark!

Both boats were twin trapezing, breeze was constant.
We started the port tack leg with the rotation pointing just aft of the daggerboard which put the spreader arm about 20mm behind the leech of the jib.
With this adjustment the two boats were almost identical in speed with the Viper paralleling the N20’s angle.

We pulled the rotation in 1cm and let the adjustment settle. Speed was up, we could accelerate harder. Now we had to increase the downhaul by 1/2 a point. Correspondingly, boat speed went up again as the drag was coming off the rig.

We went through the same routine another two times with the same result, the Viper was accelerating harder nd beginning to get ahead.

Each time we adjust the rotation setting I watch the mast head to watch for the leeward flex. On the 4th adjustment of the rotation in, I watched the mast head flex to leeward as it should do when depowering. Now our heading angle was dropping, we had over done it! We held this to observe but it was easy to see the two boats now getting closer.

This was about 3/4 of the way to the starboard layline so we opened the rotation up 2cm, got the mast head straight and started climbing back up on angle again. That  was a great leg for trimming the rotation!

Experiment 4 – tacking technique
I changed just one small movement and loved the result. I normally stay out on trapeze as long as possible and steer most of the tack from there while hauling in the mainsheet to get the boat to spin around. Coming into the tramp, I normally crack the mainsheet about 25 – 30 cm’s to allow the boat to accelerate out of the tack. This time I was cracking only about 15 cms and the boat was naturally railing up much quicker!
This meant that while I was busy with the passing the tiller around, I could feel the boat picking up the new windward hull so without looking up, I could tell I was right on the proper heading with the boat already accelerating.

We had plenty of opportunity over the weekend to observe this in action by often entering a tack ‘inside’ one of the other performance boats. Easily it was working and it worked out to about 2 boat lengths per tack… quite a lot when you add up all the tacks in a race!

Experiment 5 – I changed the amount of twist in the mainsail downwind.
By paying careful attention to the telltales in the head of the mainsail we increased the amount of twist in the mainsail to more than I would normally do but, we had 2 Nacra 20’s breathing down our neck on every run and the only way to stay with them was to change what we normally do onboard!

This does mean easing the mainsheet a fair bit and as such it places more load onto the wingmast so be mindful of the mast head when you try it. Make sure your,
1. downhaul is eased
2. the rotation is 80 – 85 degress off centre

Set the kite, get the crew weight in the proper place i.e. laterally in line with the skipper towards the rear of the boat. The skipper can sit with a foot up against the mainsheet block with their butt on the windward toe strap.

Keep the weight aft to promote ‘bow up planning’.
Heat the boat up gently, look at the telltales in the head of the mainsail and adjust the mainsheet so that they fly! Once they fly, so will you! Then concentrate on steering the boat gently to leeward. Smooth is THE key here!

Of course there was a crew on one of the Nacra 20’s that was devastatingly fast downhill and no matter what we did they would eventually steam roll us… But it was real fun trying to keep them at bay for as long as possible (thanks Damien and Cornelius it was fantastic watching you guys truck downwind).
Experiment 6 – we ran a different amount of outhaul all weekend!
This was quite interesting for me as we normally run the outhaul approximately 30mm off the boom but on Saturday we left it about 10cm’s off the boom as the first leg was a fetch followed by a hard beat. I’d figured on leaving the outhaul at 10cm’s off the boom for the fetch then pull it in for the beat. But after round the first mark there wasn’t really the opportunity to haul it in, so decided to leave it and see what happens.

The extra fullness in the lower section of the main probably helped us power through the small chop and stay in touch with the N20’s. More than normal levels of outhaul didn’t appear to rob the boat of top speed as I had anticipated.

On Sunday we pulled it in slightly i.e. about 8 – 10 cms off the boom and then concentrated on sailing ever so slightly lower upwind angels. From now on I’ll be running 8 – 10 cms of outhaul… It seems to make the boat punch through waves a little better!

So while it may have appeared to some that on Sunday we ‘found’ some secret boat speed the answers are all above. It’s up to you to put them into practice!

There was one big thing to on Sunday in the form of a series of wind shifts. Sycorax was sitting to windward of the Nacra 20’s as we proceeded on port tack it was easy to see our headings drop, so much so that i was sure we’d lose our windward perch!

The wind must have swung 15 degrees so we tacked off recognising that it was not the ‘normal’ direction and expected it would shift back again. 300 metres up the way it did shift back again and so another tack was in order. By now we’d secured a nice advantage over the N20’s who were caught on the outside of the shift.

This brings into play two things,
1. modern cat platforms tack on a dime, so hit the wind shifts!
2. getting your tacking technique adjusted so that you can tack at whim and take advantage of shifts!

Okay folks that’s all from me… see you for the Monsoon Regatta in 2 weeks time… Practice harder!

About prosailing

In Southeast Asia a long time and all the while, sailing cats. But the cat love-affair began when I finished building my first catamaran at age 15... "never again". After building 2 more Formula 16 cats in Malaysia it's really 'never again'. Now we have a large fleet of high-tech speed machines including the Nacra 20 Carbon. Then we decided to spread our wings a little more and imported the Corsair Dash 750. Now we are well on the way to establishing a Coastal One Design Dash Class. As a test bed, we had 4 Dashes take part in the Neptune Regatta and now the plans are rolling out.


4 thoughts on “Lessons from SIN Cat Nationals

  1. Hey Scott.

    Thanks mate, Great work, I will be taking onboard some of your thoughts/techniques and will try them on the 20 so you’ll have to keep getting faster can’t let you have it all your own way you know.

    Posted by Kelvin Holdt | February 23, 2010, 1:57 am
    • Ahh the aches of Monday were all worth it! Thanks to you to Kelvin for putting the whole show together. Was a great weekend and a good turnout. Plus was most excellent having the 20’s powering away and provide so very valuable ‘tuning assistance’. We’ll all get better/faster and that’s why we do this right!
      Maybe I’ll add a few more “lessons learned” over the next few days… just have to finish some artwork now!!! cheers

      Posted by prosailing | February 23, 2010, 5:43 am


  1. Pingback: 10th Singapore Catamaran Nationals « ChangiBlog - February 22, 2010

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