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Catalina/Capri 25/250 Sailor's Forums

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Keel question

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Captmorgan
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USA
220 Posts

Initially Posted - 06/15/2013 : 12:06:09

Ok I took My cat25 sk out for its maiden sail. It was about 12 to 15 knots so I only took the jib out about 50%. I liked having a furled jib it made it easy. I thought the boat handles well, but...... After heading in I realized the keel had only been down 5 turns. I headed up or let the sails out on gusts and never felt like something is wrong. I figure the area of keel was probably there but not the depth. How will it handle different with it down? I guess I'll find out next time. We started to put it down and felt the cable vibration so we pulled it back up. We were moving at 4 knots or so. I didn't know what that sound was at the time. Now I know. How do you know how far to let it down and will I feel a big difference? Thanks for any advice. Ps should you put it down before you under sail? Does it matter?

John

"The Gal-Way" 1985 SR/SK Barnegat Bay, NJ

Enjoy Sailing =) Be Safe

Happy Sailing - John

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Stinkpotter
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Djibouti
9089 Posts

Response Posted - 06/15/2013 : 12:20:39

Two differences with it mostly up: (1) the center of gravity will be higher, so the boat will tend to heel more sailing to windward, and (2) the "center of lateral resistance" will be further aft, reducing or maybe eliminating your weather helm (the tendency to turn to windward if you let go of the tiller).

In stronger winds, (1) could be dicey... I didn't have a swinger, so I can't quantify that.

If (2) leads to a neutral or lee helm (boat tends to turn away from the wind), you're losing a safety factor and, in my opinion, it just feels weird. The right amount of weather helm (1-2-finger pressure and a just a few degrees of tiller to windward) insures the boat will stop if something crazy happens, and actually increases speed somewhat.

And yes, I'd put it down before raising sails. If there isn't a particular reason for raising it, some folks leave it down to eliminate the risk of free-fall causing damage to the hull. But that's a whole different issue with lots of discussions on threads you can Search for.

Edited by - Stinkpotter on 06/15/2013 12:26:34

Davy J
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1511 Posts

Response Posted - 06/15/2013 : 12:46:44

<blockquote id="quote">quote:<hr height="1" noshade id="quote">How do you know how far to let it down and will I feel a big difference? <hr height="1" noshade id="quote"></blockquote id="quote">
I've never sailed my boat with anything other than the keel all the way down, however, I don't think you will feel anything different.
Depending on how my cable wrapped up on the winch, it takes me about 28-32 cranks to get the keel lowered all the way. I lower the keel until the cable goes slightly slack. Some sailors here like to leave tension on the cable. I don't, the cable starts to hum at a certain speed and I'm not fond of the noise.

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sethp001
Mainsheet C-25 Tech Editor

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814 Posts

Response Posted - 06/15/2013 : 18:38:47

Also, keel mostly raised would make it more like a long shallow keel rather than a short deep keel. So the boat should point better with the keel down.

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Dave5041
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3758 Posts

Response Posted - 06/15/2013 : 21:08:03

From my experience, you will find she is much more responsive with the keel down - faster tacking turns and better handling under power in addition to the other benefits mentioned. I keep a little tension on the cable, a couple of turns back from slack so the hum kicks in at about 4 kt. Its an audible speed log. Actually, the cable will always vibrate at some speed, more tension - higher speed. A slack cable's equivalent to vibration will be flopping and whipping around. I believe, not substantiated by experiment, that vibration with amplitude limited by tension might be less damaging.

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jerlim
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1484 Posts

Response Posted - 06/16/2013 : 12:29:45

Just wondering what is Catalina's position on sailing a swing keel boat w/ the keel in the up position...does anyone know their recommendations?

While the boats certainly can sail under certain conditions, isn't sailing w/ the keel up placing you in a vulnerable state, not unlike being underway w/ the pop-top up..?...just asking...

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pastmember
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Response Posted - 06/16/2013 : 16:20:34

Mine was 35 cranks then I would snug it so I could hear the hum.

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sethp001
Mainsheet C-25 Tech Editor

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814 Posts

Response Posted - 06/16/2013 : 20:03:36

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jerlim
 Just wondering what is Catalina's position on sailing a swing keel boat w/ the keel in the up position...does anyone know their recommendations?

While the boats certainly can sail under certain conditions, isn't sailing w/ the keel up placing you in a vulnerable state, not unlike being underway w/ the pop-top up..?...just asking...
<hr height="1" noshade id="quote"></blockquote id="quote">

Sailing with the keel up does put the boat in a vulnerable position. The lifting hardware is not as stout as the hanging hardware. Should the lifting hardware fail with the keel up, the keel could swing down violently and put a hole in your boat.

There is only one conceivable reason to sail with the keel up, and that is only if you find yourself out in weather a C25 should not be out in - if the boat could fall off a wave or capsize, so that the keel could swing up violently and hole the boat, it's better to have the keel in a fixed position, and all the way cranked up is the only way to lock it. This still risks the lifting hardware failing, but in this scnario it would be the lessor of two risks. Some on this forum disagree with this thinking.

Edited by - sethp001 on 06/16/2013 20:12:19

Stinkpotter
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Djibouti
9089 Posts

Response Posted - 06/16/2013 : 20:18:58

The good news is there's 1500 lbs under the boat whether it's up or down. Down, the CG of the keel itself is maybe about 2' lower, which isn't that huge. The wing keel appears to have a higher CG than the SK or FK, and has proven to be safe. If knocked down with the swing keel up, will a C-25 come back up? My guess is yes, if it doesn't take too much water through the companionway or the dumpster.

However, I would not predict the same with a C-250 WB with an empty tank (the logical analogy to the raised C-25 swinger).

Nonetheless, if I had a C-25 SK, I wouldn't pull the sails up with the keel up--that's just me.

Edited by - Stinkpotter on 06/16/2013 20:20:07

Captmorgan
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220 Posts

Response Posted - 06/17/2013 : 04:36:04

It was a mistake I will try not to repeat this . It did not. Heel too badly in 10 Ktwinds with it down 5 cranks. Probably a goody idea to always keep it 5 cranks low as a failsafe ;). I won't try it with 5 or 0 again

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hubbardbilly
1st Mate

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44 Posts

Response Posted - 06/17/2013 : 06:56:30

I would never have the sails up with the keel cranked up. Just sit at anchor with some powerboats passing by with the keel up and then put the keel down. There is such a massive change in stability when the center of gravity sits lower. I couldn't imagine trying to tack with the keel up and getting hit broadside by some wake or a wave. What a mess!

Nerd corner: I just remember way back to Naval Architecture courses: "Machine Gun Bullets Kill". What does that mean? M-G-B-K. Center of MASS, GRAVITY, BUOYANCY, AND KEEL are your forces at play from top to bottom. The if the keel is sitting high, the distance from the keel to the center of Gravity is shorter and the center of gravity is higher, both of which create more a situation that is favorable for rolling over (capsize). I found this link that's got some good basics. Bottom line, I would sail with the keel down. Motor with it up if you have to in shallow water so that the forces above the waterline are minimal:

http://www.worldwideflood.com/ark/stability/static_roll_stability.htm

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Merrick
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192 Posts

Response Posted - 06/17/2013 : 08:48:53

When we have sailed inadvertently with the keel up, I noticed more turbulence in the rudder. Never really felt unstable and we have sailed with it up, halfway down and all the way down. As with most issues you can get away with most any thing in lighter winds , but as you get into moderate or higher it's probably best to sail as she was designed, which is keel down. My old Precision 21 had a keel shaped just about like the C25 with the swinger in the up position and then a light weight center board dropped out of it. So it's not inherently dangerous. Just not ideal on a C25.

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dmpilc
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4593 Posts

Response Posted - 06/21/2013 : 10:05:39

You experienced more turbulence with the keel up because it has a flare out near the bottom similar to but a smoother curve than with a bulb keel. This also puts more of the keel's weight closer to the bottom.

Unless you are in water shallow enough to run aground, a C-25 should not be sailed with the keel up. As mentioned above, keel-lifting hardware failure will result in a cracked or broken keel trunk, which is below the water line.

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Jay Schkloven
1st Mate

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USA
84 Posts

Response Posted - 06/22/2013 : 07:55:40

Turn the keel down before putting the sails up. The boat will be very tender if you do not put it down and a large gust will spell trouble. I turn mine down until it is slack and then turn it back up two turns. This puts a bit of tension on the cable. With it down the boat will dance along in 10-12 winds. If you have not replaced the cable and do not know its age, it is an item that needs attention. Do the turning ball too. It will take about 1 hour and is worth the piece of mind.

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