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Re: maximum speed from minimum wind [Re: Robi] #85515
09/26/06 07:20 AM
09/26/06 07:20 AM
Joined: Mar 2006
Posts: 1,246
Orlando, FL
tback Offline
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tback  Offline
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Orlando, FL
At Wildcat I was using 7.5 of 10 (relative scale) going to wind and no downhaul to C mark with spi'.

Sunday, practicing with no wind, I was pulled in really tight 8-9 of 10 ... of course, I couldn't test it as we abandoned the races due to light winds.


USA 777
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Re: maximum speed from minimum wind [Re: tback] #85516
09/26/06 08:10 AM
09/26/06 08:10 AM
Joined: Jul 2004
Posts: 2,718
St Petersburg FL
Robi Offline
Carpal Tunnel
Robi  Offline
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Posts: 2,718
St Petersburg FL
Quote
At Wildcat I was using 7.5 of 10 (relative scale) going to wind and no downhaul to C mark with spi'.

Sunday, practicing with no wind, I was pulled in really tight 8-9 of 10 ... of course, I couldn't test it as we abandoned the races due to light winds.
That makes total sense. I was barely pulling on my downhaul. The speed differences were definatley noticeable. <img src="http://www.catsailor.com/forums/images/graemlins/cool.gif" alt="" />

Good info TBack. I going to need help to mark my mast. I noticed you had marks. Good thing we are having our FREE SAILING clinic for whoever wants to show up at Lake Jackson FL on OCT 7 and 8. (shameless plug!) <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

Re: maximum speed from minimum wind [Re: tback] #85517
09/26/06 08:14 AM
09/26/06 08:14 AM
Joined: Feb 2006
Posts: 3,348
F
fin. Offline
Carpal Tunnel
fin.  Offline
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Posts: 3,348
"What are your best go fast techniques for light wind? How do you prep the boat? Wax it or sand it? how about the daggers and rudders. Keep windward dagger and rudder up? Give me all the secrets for going fast in a lake. Thanks"

Quieter is faster. On Sunday, Tback and I were testing settings and I noticed the boat was faster and quieter when I moved forward. In my case, this was just in front of the shroud.

<img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" /> Pay attention! If you miss a shift in light air you'll be in irons all day. Trust me on this!


Last edited by Tikipete; 09/26/06 08:19 AM.
Re: maximum speed from minimum wind [Re: fin.] #85518
09/26/06 08:27 AM
09/26/06 08:27 AM
Joined: Feb 2004
Posts: 3,528
Looking for a Job, I got credi...
scooby_simon Offline
Hull Flying, Snow Sliding....
scooby_simon  Offline
Hull Flying, Snow Sliding....
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Looking for a Job, I got credi...
My opinion, upwind only.

Crew positions

1, Light wind and no real waves, crew to leeward hull to help lift the windward one and get well forward
2, Lightwind and some waves that are shaking the rig around, crew leeward side of the mast and as far forward as possible

Downhaul

1, Light wind it is on fairly tight
2, As soon as you start to make "proper" progress and there is a bowwave forming id consider taking it off as it this point you may have enough wind to keep the air attached to the sail(s)
3, As soon as the hulls start to get some lift I would have the DH off fully (even the odd crease in the sail att the bottom)
4, as soon as overpowered, bring the DH on again.

Mast rotation

1, very light I'll de-rotate a little to keep the sails flat
2, light (but "proper" progress) max rotation.
3, As soon as nearly powered up I rotate to the shrouds


F16 - GBR 553 - SOLD

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Re: maximum speed from minimum wind [Re: WindyHillF20] #85519
09/26/06 08:53 AM
09/26/06 08:53 AM
Joined: Sep 2005
Posts: 1,187
38.912, -95.37
_flatlander_ Offline
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Joined: Sep 2005
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38.912, -95.37
Quote
What are your best go fast techniques for light wind? Give me all the secrets for going fast in a lake. Thanks


A Hobie 18 with an SX mast and Tiger Main, right?

I'll agree with Steve and Andi on the get the hull out of the water (although may not happen until upper end of light winds). The boat stays calmer, sail more efficient. The boat's shorter than the T or N20.

Inland lakes can have a lot of chop (damned powerboats) and in our experience a stock Hobie 18 needed some power to help drive through the chop (very flat didn't work). I can't speak to the "modern" Tiger main.

All posts good advice, there will be variables.


John H16, H14
Re: maximum speed from minimum wind [Re: NCSUtrey] #85520
09/26/06 09:11 AM
09/26/06 09:11 AM
Joined: Jul 2001
Posts: 364
Andrew Offline
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Andrew  Offline
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Posts: 364
Quote
Robbie was quite clear in telling us that sending crew leeward in light wind was pointless when going upwind. I'm not going to argue with him...his record is much better than mine, and most everyone else here as well.


Robbie's mostly a T sailor? Light-air techniques vary from boat to boat just as medium- and heavy-air techniques do. My metric Nacras need to be sailed bows-down, but the 20 needs to have the leeward bow just touching the water. So it varies. Good luck.


Andrew Tatton Nacra 20 "Wiggle Stick" #266 Nacra 18 Square #12
Re: maximum speed from minimum wind [Re: _flatlander_] #85521
09/26/06 10:44 AM
09/26/06 10:44 AM
Joined: Apr 2003
Posts: 440
Graham, NC
WindyHillF20 Offline OP
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WindyHillF20  Offline OP
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Graham, NC
Yes, SX mast and tiger main. Running a spin as well. The tiger main really changes the way the boat feels, its hard to get used to. I've been rotating the mast more and more to get what seems to be the right shape and the tales to flow on both sides. Have tightened the diamonds to 500lbs to get some pre-bend. Think the comptip is bending too much, squaretop seems disturbed. Have installed tell tales on the lower portion of the main but as of yet not been back in the water.Thanks so much for the great advice from all. Are you all saying that boat prep is not important? Shouldn't it at least be cleaned and waxed? One last question, mast rake for light winds- what do the tigers do? Mine is back, second hole from bottom on forestay adjuster. Forward rake requires repositioning of spin pole height on my boat.

Re: maximum speed from minimum wind [Re: WindyHillF20] #85522
09/26/06 11:30 AM
09/26/06 11:30 AM
Joined: Jun 2006
Posts: 308
Reno NV
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Rhino1302 Offline
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Posts: 308
Reno NV
Cleaning and waxing your boat may gain you a few seconds over the length of a race. If you are an excellent skipper in a highly competitive one design fleet those seconds may be critical.

In very light/shifty conditions, getting into the right wind can make a difference on the order of tens of minutes. Boat handling (sail trim, weight placement, clean mark rounding) can make a difference on the order of minutes.

That being said, a few second lead can turn into a few minute lead if you can get to the first mark before the pack does. Nothing nicer than looking back at the mark and seeing all of your competitors trying to round at the same time in virtually no wind. And there's nothing worse than having that few minute lead turn back into a few second lead as the wind fills in from behind.

Re: maximum speed from minimum wind [Re: WindyHillF20] #85523
09/26/06 12:04 PM
09/26/06 12:04 PM
Joined: Jun 2001
Posts: 9,582
North-West Europe
Wouter Offline
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Wouter  Offline
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Posts: 9,582
North-West Europe

If the comtip is too bending then DON'T rotate your mast too much. Over rotations will make the top of the leech fall away too soon. Present the top of the sail with the mast stiff direction of the mast top and that is the fore-aft plane of the mast = relatively little rotation.

Wouter


Wouter Hijink
Formula 16 NED 243 (one-off; homebuild)
The Netherlands
Re: maximum speed from minimum wind [Re: WindyHillF20] #85524
09/26/06 01:10 PM
09/26/06 01:10 PM
Joined: Sep 2005
Posts: 1,187
38.912, -95.37
_flatlander_ Offline
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38.912, -95.37
Before making any wholesale changes (oops, I guess you already sort of did that) I'd go with what I knew was fast from the original setup and then try individual changes. For instance, we found the fast setup w/the 18 to be no rake (2nd hole from the top), no pre-bend. The Tiger main luff will dictate your prebend.


John H16, H14
Re: maximum speed from minimum wind [Re: WindyHillF20] #85525
09/27/06 09:17 AM
09/27/06 09:17 AM
Joined: Jun 2001
Posts: 1,459
Annapolis,MD
Keith Offline
veteran
Keith  Offline
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Joined: Jun 2001
Posts: 1,459
Annapolis,MD
Quote
Yes, SX mast and tiger main. Running a spin as well. The tiger main really changes the way the boat feels, its hard to get used to. I've been rotating the mast more and more to get what seems to be the right shape and the tales to flow on both sides. Have tightened the diamonds to 500lbs to get some pre-bend. Think the comptip is bending too much, squaretop seems disturbed. Have installed tell tales on the lower portion of the main but as of yet not been back in the water.Thanks so much for the great advice from all. Are you all saying that boat prep is not important? Shouldn't it at least be cleaned and waxed? One last question, mast rake for light winds- what do the tigers do? Mine is back, second hole from bottom on forestay adjuster. Forward rake requires repositioning of spin pole height on my boat.


Different boats require different variations of the techniques for light air.

Actually trying to get the windward hull out in very light stuff is mostly a waste. Note that I said very light. In most cases you will end up depressing the leeward hull significantly to achieve it, and the drag savings will be minimal. We've tried trapping to leeward to get the windward hull out, it's fun but useless from a speed standpoint.

Just about everything else I've sailed has benefited from crew on the lee bow and skipper at or on the crossbeam, near the mast if possible. In that position the skipper should run all the sails, as it is often very inconvenient for the crew to do the jib without moving around, and the skipper can actually see what the sials are doing. Mast rake can play a big part in how far the skipper and crew need to be forward to get the sterns free.

As for tacking and jibing - I've found that the attention needs to be placed on keeping the boat moving through the water, and crew weight placement can be more important here than sail handling. Worry about keeping the hulls moving through the water and getting the sails over second. Trying to do a roll tack in the really light stuff is mostly a waste. Consider having the crew cross the boat in front of the mast instead of behind can help.

For the most part, stay in the middle of the course and try to take the most direct line to the marks. Chasing breezes on the outside of the course often leaves you without wind outside the course with more distance to recover.

That all having been said - the Hobie-18 is a big time stern dragger, and mast rake only made it worse. In almost all conditions I found that a lot of mast rake made the boat an absolute dog downwind, even if the sterns weren't dragging. Even after I added the spin, in most conditions I ran the mast all the forward. If I raked the mast in anticipation of heavy air that did not materialize I unraked it on the water to keep from dying. Can't emphasize this enough with the 18.

Re: maximum speed from minimum wind [Re: SteveT] #85526
09/28/06 03:55 PM
09/28/06 03:55 PM
Joined: Jan 2004
Posts: 330
S
srm Offline
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srm  Offline
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Joined: Jan 2004
Posts: 330
It has been touched on, but I would reiterate that finding the wind and sailing the boat well are critical to going fast in the super light stuff. I very rarely change the way I rig my boat (Hobie 17). Possiby kick the windward rudder in the light stuff.

Having good wind indicators (VHS Tape) is very handy. I don't look at the tell tails on my sail too much, but I'll glance up at the top ones if the boat feels sluggish to see if the lee side is stalled. It's best to get a feel for the boat so you don't have to look at it (get your head out of the boat). I try to spend 2/3 of my time looking around for wind by watching the water and the speed and angle of other boats. When the wind is light, you can actually listen to the bow ripple and the flutter of the VCR tape to hear accelerations. Also, if you turn off the rachet on your main blocks you can more easily feel changes in pressure. I almost constantly adjust my mainsheet, one or two inches out in lulls and one or two inches in for puffs.

Just some suggestions.

sm

Re: maximum speed from minimum wind [Re: srm] #85527
09/28/06 04:39 PM
09/28/06 04:39 PM
Joined: Jun 2001
Posts: 131
Ohio
Jamie Diamond Offline
member
Jamie Diamond  Offline
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Joined: Jun 2001
Posts: 131
Ohio
I would suggest looking at this a different way. Your foils, that is your boards and rudders, are your "underwater sails". And just like you can benefit from more sail area in very light winds, I believe you can generally benefit from more foils at very low boatspeeds.

Hence, in very light air, I keep all of my foils down all the way around the course. As boat speed goes up I consider reducing my foils. So in medium to medium+ I might start pulling my boards part way up for downwind. In really heavy air I might pull my boards part way up and have them part way up all the way around the course.
The way I look at it you need more foil in light air to prevent stalling the foils (very high drag) and at low boat speed the surface drag from the foils operating with good flow is minimal. At greater boatspeeds the foils will not stall (so you need less of them) but the surface drag begins to increase significantly (so you pull them up) reducing surface area and surface drag.

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