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Tacking angles?


MisterMoon

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I've got some miles on my CS17 now and I'm getting better at sailing her. After a lot of analysis of my GPS tracks, I've figured out that my CS17 tacks through between 100 and 104 degrees when going to windward when going for best VMG. This isn't bad in my experience. But everyone always talks about tacking through 90 degrees. What about you guys? Anyone doing better? And if so, how are you doing it?

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I once spent some time with a GPS and compass on my CS 17 getting some measurements for a polar diagram. This was on a lake with a steady light breeze. The disclaimer is that I only did one set of readings so accuracy is not guaranteed. My best VMG to windward was at 50 degrees ie 100 degrees between tacks. I could sail closer but it was slower.

Cheers

Peter HK

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We've gotten close to 100 or maybe even 95 according to GPS but speed is slow, and in a current or wind not good. Last week we took the boat out in some heavy weather, unreefed and the boat pointed upwind very tight and sweet, speed was slow but we did go upwind. We compensated by letting her drift back to 55-60 then tightened up again to keep better speed up.

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Yes, some modern race boats with deep keels and clean foils can tack under 90 degrees, but the "groove" is often narrow and even they wind up footing off in anything other than the right wind and sea.

Check out what Volvo 70s can do. I think you will be surprised.

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The Volvo 70's would be a poor example of windward ability. If you watch them, you'll note their sheets are fairly free up wind, so tacking angles of 95 to 100 degrees would be typical for this. They would get crushed in a tacking duel with a 'round the buoys machine (as has been proven when they arrive in port and a pick up duel comes out to meet them). As wind strengths increase so do tacking angles, though some designs seem better equipped for up wind work, such as the last of the AC monohulls, which could tack through 70 degrees and stayed in the groove in the 80's pretty regularly. Generally, each design will have a groove, where it makes it's best VMG under a given wind speed, you just have to find it.

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Feb of last year delivered a Tartan 41, deep keel, tall rig from Rockport Texas to Isla Mujeres. First stop was Progreso, Yucatan.

We spent 6 days , on port tack, beating into 25 knots and 4-7 foot seas. That boat with it's deep fin, would sail at 27 degrees apparent, which was most likely about 45 degrees true. But boat speed suffered greatly- she's go much better at 33 degrees apparent, or about 50, 52 degrees true.

But on that course, you/'re kinda stuck- too far off wind and you don't make the Yucatan, tack over to a starboard tack, and you sail into the Yucatan current, and wind up in Mississippi :P

Sea state has a huge affect on course, as does conditions. I realize a CS17 isn't gonna sail in conditions like that- just giving this as an example of a racing type boat....

Trust me- it wasn't a great deal of fun.

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When racing lightnings, we'd bear off a bit in a puff and gain speed and whe the wind died, we'd pinch up and gain more ground towards the mark. Then bear off again in anticipation of the next puff. This netted the biggest gain towards the windward mark.

Interesting. I usually do the opposite; head up in puffs and bear off in lulls. Your technique seems counter-intuitive to me, but at the same time I can maybe see some logic in it. I'll have to try your approach and watch my VMG.

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Howdy Charlie, sorry but I have not left the compound even though last year was the second year of taking care of FIL which passed mid Oct. So since then I have been cleaning up his house and doing a wee bit of boat work on a new fishing skiff with some leftover cedar for Mamma and me. Gas prices has had us on a short leash. Hope things are going okay for you. Give me a jingle anytime. Now back to your regular program.

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Maybe you need to tune your iron jib or maybe you need a boat like mine. I can run at zero degrees to windward. ;)

You got me there. My aluminum breeze works really well and I can go eight knots dead to windward when I want to. The racing authorities tend to frown on such frivolous behavior, however.

I'm looking forward to my next event, the Florida120, where if I get tired of bashing to windward while getting a bad case of monkey butt from sitting on the rail all day I can crank up the Tohatsu any time my fun-o-meter starts getting low.

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  • 2 weeks later...

100 degrees sounds right for the CS17- that's about what I do, and she's competetive w/ other boats her size. A small jib might give her 2-3 degrees if the sailplan were adjusted to keep the balance, but where I've noticed the CS 17 needs help is off the wind in light conditions, against local boats in Beaufort that have large mains and small jibs and reach a bit faster in less than 8 knots. Above that, the CS has enough sail to leap ahead and not need reefing until 15 18 upwind and higher off the wind.

If Mistermoon is like me and sailed sloops all his life, that's the big adjustment- to the ketch rig- and that's just practice, practice, practice. Overall, it's a much easier rig to sail but not without it's quirks. The main thing I've had trouble doing is getting away from a dock when the current is pushing towards the dock and the wind pushing towards the dock as well. In a 15' sloop, I have no trouble but can't get cat-ketch to get away in the same manner. I know it's a balance issue and the light bulb might click any day, but for now .....

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100 degrees sounds right for the CS17- that's about what I do, and she's competetive w/ other boats her size. A small jib might give her 2-3 degrees if the sailplan were adjusted to keep the balance, but where I've noticed the CS 17 needs help is off the wind in light conditions, against local boats in Beaufort that have large mains and small jibs and reach a bit faster in less than 8 knots. Above that, the CS has enough sail to leap ahead and not need reefing until 15 18 upwind and higher off the wind.

If Mistermoon is like me and sailed sloops all his life, that's the big adjustment- to the ketch rig- and that's just practice, practice, practice. Overall, it's a much easier rig to sail but not without it's quirks.

Your observations are about spot on. The CS17 is pretty helpless downwind in light air. I think it's a combination of both sail area and mast height. THis is one reason I want a staysail.

I was sailing today in company with Scott Widmier's turbo Suncat (huge, non standard rig on his boat.) When it got really light downwind and reaching, he had the best of me. Once we saw over 10, I had to spill air or overtrim for him to stay close.

The standard CS17 rig really comes into it's own in 12-18. The first reef goes in for upwind sailing at around 16 for me, but I've weathered gusts over 20 without too much drama. If the water's flat and it's blowing 20-25, keep it full sail for a heck of a fun ride downwind. I was pretty conservative for this year's EC/UM, however. I stayed double reefed about the entire time. I didn't want be caught out with too much sail in the middle of the night when it was getting colder and colder. It seemed and still seems rational to me.

I love the ketch rig, though. What's amazing is how easily you can maneuver in close quarters under sail power along just by adjusting the trim of the main and mizzen. It's great on a starting line with sloops becuase you can just spin and spin and then take off.

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The CS17 is pretty helpless downwind in light air.

I think just about if not all boats are helpless downwind in light air. It is faster to "tack downwind" (gybe back and forth). It varies a good bit as to what is the best TWA between designs. But for light winds most fall in the range of 150º -135º from true wind.

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"I love the ketch rig, though. What's amazing is how easily you can maneuver in close quarters under sail power along just by adjusting the trim of the main and mizzen. It's great on a starting line with sloops becuase you can just spin and spin and then take off."- From Mistermoon.

I guess I just need to get you out there and watch or something- I'm so much more comfortable doing close quarter maneuvers in a small sloop rigged boat!

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When racing lightnings, we'd bear off a bit in a puff and gain speed and whe the wind died, we'd pinch up and gain more ground towards the mark. Then bear off again in anticipation of the next puff. This netted the biggest gain towards the windward mark.

Interesting. I usually do the opposite; head up in puffs and bear off in lulls. Your technique seems counter-intuitive to me, but at the same time I can maybe see some logic in it. I'll have to try your approach and watch my VMG.

When racing lightnings, we'd bear off a bit in a puff and gain speed and whe the wind died, we'd pinch up and gain more ground towards the mark. Then bear off again in anticipation of the next puff. This netted the biggest gain towards the windward mark.

Interesting. I usually do the opposite; head up in puffs and bear off in lulls. Your technique seems counter-intuitive to me, but at the same time I can maybe see some logic in it. I'll have to try your approach and watch my VMG.

If you bear off in a lull, you'll loose a lot of ground that you've made up during the good wind and playing the lifts. Object is to make the mark, not go fast.

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