Sailing with keel UP
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Accidently a couple times with our original C-22, then I realized how insane it was. Better off just dropping the sails and motoring.
Don
Don
You probably remember that day last summer when we were chasing you with the keel up, and couldn't catch up for diddley. When we finally corrected our mistake we only did a little better, like 2% better, but you still were pointing higher.
It was a light air day, though. I've wondered ever since if the effect of the keel on speed and pointing might be more pronounced as the wind builds.
There for sure is a complex relationship between keel profile, keel dimension, speed through the water, and lift generated. In general, deeper narrower keels will generate more lift, but the boat has to be moving well. Below a certain speed the keel generates much less lift and the boat will not point nearly as well.
Boats with long shallow keels (shoal) might point a bit better in low boat speed conditions, but a lot of that is just because they limit side-slip better in those conditions.
If a boat has a polar graph created by the designer, this relationship can be easily be seen. The keel on the First 260 is deep (6 feet) and narrow. So the boat does not point great until about 6-8 knots of breeze, then it's off to the moon! You can see the optimal true upwind angles at the ticks on the chart below going from about 45 true (very respectable for most boats) in light air to about 37 in breeze. BIG difference!
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oddly enough I was out yesterday and bored no wind water was like glass and was just motoring around listening to the radio.
Anyway decided to see what keel up keel down effect was on speed.
This isn't scientific but is enough for me. I set my throttle 1/4 or so till speed was holding right about 4kts and held that speed for about 5 mins. Then I raised the keel same throttle same direction wind same waves same speed changed maybe and I say maybe on the high end up .1 kts over a 5 min period and personally I'd say it was so close that it was virtually non existent.
This was motoring not sailing I'm sure there are differences don't need them explained to me, in the end, in my opinion the difference is so small that it's near meaningless. I've done the same thing sailing before and honestly couldn't tell much of a difference there either.
Honestly whenever possible I leave my keel down even while motoring mainly cause it seems to dampen the rocking a little bit I know not much but a little also I like the fact that anything I hit hits the keel before it hits the rudder or motor as well.
So while I'm sure there is a difference in speed I just couldn't find it.
Anyway decided to see what keel up keel down effect was on speed.
This isn't scientific but is enough for me. I set my throttle 1/4 or so till speed was holding right about 4kts and held that speed for about 5 mins. Then I raised the keel same throttle same direction wind same waves same speed changed maybe and I say maybe on the high end up .1 kts over a 5 min period and personally I'd say it was so close that it was virtually non existent.
This was motoring not sailing I'm sure there are differences don't need them explained to me, in the end, in my opinion the difference is so small that it's near meaningless. I've done the same thing sailing before and honestly couldn't tell much of a difference there either.
Honestly whenever possible I leave my keel down even while motoring mainly cause it seems to dampen the rocking a little bit I know not much but a little also I like the fact that anything I hit hits the keel before it hits the rudder or motor as well.
So while I'm sure there is a difference in speed I just couldn't find it.
I should have said more - I'm upriver on the Caloosahatchee river (North Fort Myers), it is a good 5-7 miles to get tp a wide sailing area; the depths here(except for the channel are 3.5 - 6.0 feet and narrow on the charts, so it's a pretty sure thing that I will bottom the keel down which I prefer not to do.. I just want to sail a little (haven't since I bought her), and see how she feels. I thought with a reefed main OR just a headsail in low winds it would be comparable to a Compac that has no swing keel. Since I've never sailed her, I thought I'd better ask for help. Not interested in how she points, or how fast she can go, just a little easy smooth sail, and will she be "tippy"?
Good point Don. So how about lowering the keel just a bit so it has some bite, but not all the way down where it will likely ground, and not locked in, so it can be bumped up if it hits anything? And don't you all raise thee keel when on a run (assuming you have a swing keel)?
My first C-22 was a swing keel version, our current C-22 is a wing keeled version. The original boat was kept in fresh water in the midwest and slipped her every year from April/May to October/November. The keel was pretty much always down, and I kept the cable tight. Yes it would "Hum" when we sailed, but I kind of like it, and with it tight, "if" the keel hit something, (like maybe a submerged wing dam on the Mississippi River?), when the keel came back down, I didn't have to worry about the keel damaging the back of the keel trunk. I know folks try bringing the keel back and playing with the angle of the keel, but again, the swing keel on the C-22 was designed to make the boat easier to trailer. Because we didn't trailer the boat like we currently do, I forgot to lower the keel several times during our annual spring launching. And yes, we would pull the keel up when beaching, but the sails were stowed before we beached.
Small boats can flip when not operated correctly, and in accordance with the manufacturer instructions, just ask Roger Macgregor......
Don
Small boats can flip when not operated correctly, and in accordance with the manufacturer instructions, just ask Roger Macgregor......
Don
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If you are talking about a ballasted keel, failing to lower the keel to at least a halfway point could bring some serious stability problems. On the other hand if you are talking about a center board then the only loss is pointing ability when going to weather. When sailing down wind it is actually encouraged to raise the center board to reduce drag as pointing ability is not affected. When we had a ballasted keel boat I would keep a lock bolt on the keel to prevent it from jack knifing back into the trunk in case of a knockdown but would remove the bolt when approaching shallow water just in case we grounded.
One other point that I didn't make in my first post....
The keel profile is only hydrodynamic correct when all the way down. Setting it in various mid-point positions, or worse not lowering it all all means its just low ballast and some lateral resistance.
QUOTE="Benny17441, post: 1272560, member: 75512"]If you are talking about a ballasted keel, failing to lower the keel to at least a halfway point could bring some serious stability problems. On the other hand if you are talking about a center board then the only loss is pointing ability when going to weather. When sailing down wind it is actually encouraged to raise the center board to reduce drag as pointing ability is not affected. When we had a ballasted keel boat I would keep a lock bolt on the keel to prevent it from jack knifing back into the trunk in case of a knockdown but would remove the bolt when approaching shallow water just in case we grounded.[/QUOTE]
Being a C-22 Forum, we're talking about a swing keel'ed version of the C-22. So your response doesn't apply to the C-22.
Don
Being a C-22 Forum, we're talking about a swing keel'ed version of the C-22. So your response doesn't apply to the C-22.
Don
I use to sail the Caloosahatche river (known as mile wide and inch deep) around the Ft Myers drawbridge (in the late 70s) and further down river in a Luger 21 swing keel, mostly up for same reason and only partly down (about 50%) the rest of the time. Later i went in the water and found out how much to lower it to just be shallower than my tiltup rudder. It turned out to be quite easy to feel the rudder tilt and adjust course to avoid smacking the keel . But of course if was too windy I cranked it all up and sailed back home on the iron jib. Just a thought, now own a cat 22 and plan on same trick in shallow areas up here in Pensacola until I get the depth guage installed.
my experience is quite different from allen's. I ALWAYS raise my keel when motoring (unless really rough, then I leave it down for stability). I almost always see a .3 to .5mph gain (when you are motoring for an hr, that's a big deal... I have also been known to raise the keel going downwind when racing (cough gene neill cough) but NEVER in an official race...
Gene, I sort of remember something like that, was that last trip out with all the weeds? did I have my keel up too? I'm not as young as you, I forget these things LOL
Gene, I sort of remember something like that, was that last trip out with all the weeds? did I have my keel up too? I'm not as young as you, I forget these things LOL
No, it was last year, one of Peewee's first sails. Both of us passed a larger 28'-ish Hunter later that day, if that jogs your mammary.
I too always raise the keel when motoring ... but that's because the only time I'm motoring is when I'm in (or approaching) thin water, or when there's no wind (in which case sea state is not an issue anyway). I'm quite averse to using my keel as an "audio depthfinder", which I would be doing very soon, if I gave myself the chance to forget it was down.
"Sails up, keel down. Sails down, keel up". It's a strict rule aboard s/v Daydream. It prevents knockdowns and groundings!
I too always raise the keel when motoring ... but that's because the only time I'm motoring is when I'm in (or approaching) thin water, or when there's no wind (in which case sea state is not an issue anyway). I'm quite averse to using my keel as an "audio depthfinder", which I would be doing very soon, if I gave myself the chance to forget it was down.
"Sails up, keel down. Sails down, keel up". It's a strict rule aboard s/v Daydream. It prevents knockdowns and groundings!
When I was sailing my Venture 22 (VERY similar to a C22), I always had the keel bolted down for safety. I was glad I did all the times I was knocked down! Once, after damaging the keel I had to motor/sail with the keel up. It's OK downwind or motoring, but you are "working without a net" - if you do go over you WILL "go over"!
I think if you want an increase in speed, re-shape the keel so it's more hydro-dynamic, and pull the cable forward into a slot at the back of the keel (the cable actually drags more than the keel!)
druid
I think if you want an increase in speed, re-shape the keel so it's more hydro-dynamic, and pull the cable forward into a slot at the back of the keel (the cable actually drags more than the keel!)
druid