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Keel position

Posted: Wed Jul 18, 2012 8:44 pm
by 1st Sail
Question regarding keel position. Sailed hard all day Monday, winds 12-16mph. main on second reef, 110 jib. SOG avg. 5-6.5mph. Reach. heel angle 15-30 degrees depending on winds and gusts. keel set approx. 2ft. No noticeable slip (verified by wake trail and chart plotter). Would you increase or decrease keel depth to increase speed and reduce heel?
I don't get great conditions like that very often. Had a blast. In the higher winds I was running upper 5's to mid 6's and could close on some of the real sail boats. In lower winds they had more sail and would slowly walk away from me. Played tag with an S24.5 but just couldn't stay with it in lower winds. Considering what the Mac is designed to due a respectable showing.

Re: Keel position

Posted: Thu Jul 19, 2012 1:25 am
by Catigale
I don't think your keel position has a big effect. Unlike the :macx: , you chant change the centre of resistance and balance the helm with a daggerboard..

Would be interesting to see the track to see how well you pointed...tacking through 110 degrees or better is respectable indeed

Re: Keel position

Posted: Thu Jul 19, 2012 10:53 am
by Steve K
Catigale is right in that respect.

You may take a little drag off, in certain conditions, by raising the board some. I dont' know if this would translate to a noticeable gain in speed, but as long as you can still point, it can't hurt.

Where I find the daggerboard up being a great help is downwind, particularly wing on wing. It's easier to keep the boat from jibing on it's own and keep her pointed straight down. If the wind direction changes slightly, the boat more readily follows that change. On a run, slightly off DDW, I will also raise the board, as long as I can stay on course. This will gain me a knot or more, in some cases. These boats will hold a good course, if speed is up on most downwind points of sail, with no board at all (speaking of X and D.... no experience with M, but hull shape is kind of in-between, so would suspect it would be similar).

I'm speaking here, of the board all the way up or all the way down. I haven't really tried mid settings

If the board can be raised, it's not really working and is just adding drag, is a good thumb rule. (given the up-haul is as delivered and you haven't added a purchase to it....... on this, I couldn't say)

Best Breezes,
Steve K.
Mac

Re: Keel position

Posted: Thu Jul 19, 2012 11:13 am
by robbarnes1965
I also like pulling the dagger up just before scooting across sand bars :)

Re: Keel position

Posted: Thu Jul 19, 2012 12:45 pm
by ronacarme
Recalling my old 26D, I would think the 110 jib and reefed main on a close reach would be best balanced ( for a roughly neutral or not lee helm) with the daggerboard fully down. Broad reaching (or downwind) I recall that the D held course easily with the daggerboard up partly (or fully), which would shift the underwater hull's center of lateral resistance aft a bit (tho obviously not so much as rearwardly swinging the CB on our current 26X), to give a hint of the stabilizing effect of the fletching on the trailing end of an arrow in flight.
Also, has not someone suggested that at least partly raising a daggerboard?centerboard might reduce the possiblity of tripping over it when hit by a breaking beam sea, while lying ahull in severe storm conditons? I hope never to get anywhere close to such conditions and find out in person.
Ron

Re: Keel position

Posted: Thu Jul 19, 2012 6:01 pm
by mastreb
In the case you described, pulling the board up between full and half deployed would have reduced drag a little with no ill effects.

You can think of board position as a continuum between fully down while pointing (which on these boats is at about 50 degrees) to fully up while running (180 degrees). So if true wind is at 90d, you can pull up to 75% deployed, if its at 120d, you can pull up to 50% deployed, and if its at 150d you can pull up to 25% deployed and get all the benefit against sideslip that you need with the minimum possible drag.

That said, daggerboard drag is the least important thing you can trim on the boat. I keep the board fully deployed for simplicity's sake unless I'm really trying to eek that extra half knot out of the boat and I've already done everything I can do with the sheets. The daggerboard is the last thing I trim, if I trim it, and I only do that if I'm consistently heading the same direction for ten or more minutes (which is rare here in San Diego Bay).

I'm more likely to pull the windward rudder up because it's also beneficial and easier to manage from the helm during a tack. Swapping the rudders on a tack also automatically clears them of seaweed which is a constant problem here. I pull the dagger up more often to clear it than for performance reasons.

Re: Keel position

Posted: Thu Jul 19, 2012 6:29 pm
by Catigale
Anytime Stevek agrees with me on a sailing point I'm having a better than average day...... :D

Re: Keel position

Posted: Thu Jul 19, 2012 9:15 pm
by 1st Sail
the boat pointed well. I was estimating approx. 50' +\- based on compass heading and wave pattern compass line. I was just trying to squeak as much speed possible out of the boat. Never had the opportunity to race /chase / be chased down by other boats before. Needless to say it was a lot of fun. We were doing 5mi. runs up and down the lake mostly on a reach. In retrospece I probably had the main trimmed a little flat. It was very clean and no stress wrinkles off the slugs or reef lines. Tell tales were all streaming back clean. If I get those conditions again i will add some belly to the sale and watch the speed.

Re: Keel position

Posted: Fri Jul 20, 2012 7:01 am
by SeamanLou
Anyone ever seen polars on a V-22?

Re: Keel position

Posted: Fri Jul 20, 2012 7:54 am
by Steve K
Catigale wrote:Anytime Stevek agrees with me on a sailing point I'm having a better than average day...... :D
Really :?:
Had no idea.

I think you give some great comment and advice here and thank you for some of your great opinions. :)
Didn't realize I may have sounded negative to some of your thoughts.

I guess I may look at things from a different direction sometimes, but you are a great asset to this forum.

Keep up the great work :wink:

And truly............

Best Breezes to you and yours,
Steve K.
Mac26D "Three Sheets"

Re: Keel position

Posted: Fri Jul 20, 2012 11:26 pm
by Catigale
No implied negativity intended , my bad. what I was implying is your abilities far outstrip my knowledge base, rather than disagreement .... :D

I suck at sailing , and admire folks like you who are masters of speed. My 14 year old twins both helm better than I, which I normally wouldnt mind, but they were better at age 7 too. :|

Re: Keel position

Posted: Sat Jul 21, 2012 8:00 am
by Steve K
Catigale wrote:No implied negativity intended , my bad. what I was implying is your abilities far outstrip my knowledge base, rather than disagreement .... :D

I suck at sailing , and admire folks like you who are masters of speed. My 14 year old twins both helm better than I, which I normally wouldnt mind, but they were better at age 7 too. :|
Cat,
Well, I really suck at it too, compared to some people here. The proof is when Newell can be 2 miles behind me in the morning and catch and pass me by noon :? (only in his D boat though). When he's sailing his X, I can usually stay out front :wink:

There are things I know, but my problem is, I've never been able to get enough time to really get good at sailing the boat. When I only get out there a couple times per year, I end up spending a lot of time re-learning the boat (what she likes.... best trim..... best point of sail for best speed.......... okay, now I'm going fast, but am I headed to the mark? etc.).

Several years ago, my Windex broke (it was a cheap one). That same year I sent my sails for cleaning (Sail Care). and when you get them back, you get these pretty, white sails and a package of telltails. Well, I had this great idea that I would do without these sailing aids and try to learn to read the wind without them. If I sailed more, and if my sailing grounds were a little less flukey (only sailed @ Mead for about 5 years now), I might be better at it, by now. My new main came with tells along the leech and they are encouraging me to put them back on my head sails. I may do this before my next trip.

I'm getting way off topic here, but you finally retire........... you think you're finally going to get a lot more sailing time............. you notice the house needs some improvements................. two years later, you're thinking, "okay, after this project, I'm going to get some more sailing time" :?

Gotta quit doing this to myself :wink:

Always a pleasure, Cat.

Best Breezes,
Steve K.

Re: Keel position

Posted: Sat Jul 21, 2012 6:30 pm
by Catigale
:D :D :D

Its gratifying to enjoy something so much that I suck at.....

Running the club, I've seen a couple of urban kids who had never seen water grab the helm and keep the boat on perfect course to the wind...first time on the tiller.... :| :| :|

I'll stay out of Newell's way....he'll probably be back at the dock while I'm still tacking to the start line.... :|

Re: Keel position

Posted: Sat Jul 21, 2012 7:15 pm
by Steve K
Yea,
Gave the sheets to my wife, awhile back, for the first time, and she's a natural at it. Doesn't know anything about sailing (save what she has picked up while out with me), but she has a knack for trimming the sheets :)

About Newell;
not only is he fast, he's relentless......... always tweakng things, always adjusting. The last race we were in together, he caught me around the mark, even though I had one of the cleanest starts ever. He ended up about a thousand yards ahead of me..... it was 90+ degrees ......... wind died .......... all the other boats quit. But me and Newell sat there for a long time, waiting for the breeze to return. Right before I had heat stroke, I gave in also. Newell won another cup :( . Gotta hand it to him, he continued waiting for wind and actually did finish. (diehard :!: )
I think one more win will give him a full services for six :wink:

And, our cup (as in founders day cup)...... well, it's actually a cup, a Coleman, stainless steel coffee cup. It is engraved with the race date, etc.

YEP :!: it's a highly coveted trophy in these parts :) I finally got one a couple years ago :D

Best Breezes,
SK