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Catalina 25 Specific Forum

Need some info tonight (20 Dec) if possible.

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NCBrew
Captain

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USA
338 Posts

Initially Posted - 12/20/2009 : 15:58:35

A little info please.

I will be motoring in deep water (50 ft) with ship traffic for the first few miles of my trip. I will then be in about 6 feet of water and no traffic in the Dismal Swamp canal after leaving Norfolk, VA.

My question is should I put the swing keel all the way down. Would that give me more stability. Will it slow me down?

Is it OK to put it halfway down?

I never owned a swing keel before.

NCBrew

1998 Catalina 250WK
Ravaging
Albemarle Sound,NC

I spent most of my money on boats and beer, the rest I just wasted.

Edited by - on

Ed Cassidy
Captain

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Response Posted - 12/20/2009 : 16:09:30

For motoring, leave the keel up. It will not assist at all when motoring.

Edited by - on

NCBrew
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Response Posted - 12/20/2009 : 16:21:37

Thanks Ed

Edited by - on

Steve Milby
Past Commodore

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Response Posted - 12/20/2009 : 18:25:35

The swing keel should be down at all times. If the cable or support mechanism should ever fail suddenly while the keel is raised, the sudden drop of 1500 lbs. is likely to cause severe structural damage to the boat. This is only likely to happen if the cable and mechanism are not well maintained, but it has happened often enough to be a serious concern. Most swing keel owners on the forum are very conscientious about maintaining them. I haven't looked recently, but others have said that, in the owner's manual, Catalina recommends that the keel be kept down at all times. It is a subject of controversy here, but I have experimented with swing keel C25s and have found no benefit to be gained by raising the keel. One would think that raising it would reduce drag, but, when it's raised, the keel isn't raised out of the water. It's just rotated up against the hull bottom, so, the wetted surface (and thus the amount of drag) hasn't been reduced, but the boat's stability and righting moment have been reduced. If you balance the benefits that you are losing against the dubious gain you are getting by raising the keel, the answer is clear.

I was motoring on a friend's heavily ballasted full-keel sailboat on the Severn River in Annapolis when a big Sea Ray overtook us from behind and nearly rolled our mast into the water with his wake. You can never anticipate the crazy things that might happen on the water, and it's best to never reduce the boat's stability or righting moment.

Edited by - Steve Milby on 12/20/2009 18:45:59

bigelowp
Master Marine Consultant

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Response Posted - 12/20/2009 : 18:35:06

God Speed -- may your journey be calm and safe regardless of swing keel position

Edited by - on

Even Chance
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Response Posted - 12/20/2009 : 18:38:02

Steve's half right. Put the keel down as soon as you have enough water to do so. Leave it down. You will need it to help you track through Hampton Roads. Should you run aground, crank it up a few clicks to get moving, then drop it back down.

The "keel up/keel down" debate is an old and unresolved argument in this forum. In fact, the C25 handbook says to leave the keel UP when docked or moored in salt water. My theory about this is that it helps preserve the keel cable, and reduces the stresses on the pivot hardware in storms or waves.

For the record, my C25 swing keel has been in salt water (docked UP) for twenty-one years without any problem. I replace the keel cable every 2 - 3 years, and have replaced the hanger hardware twice in twelve years. Other people have a different opinion about leaving it up or down, but the advice is almost unanimous (see above) to leave the keel all the way down when moving, whenever possible.

Edited by - Even Chance on 12/20/2009 18:39:31

jerlim
Master Marine Consultant

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Response Posted - 12/20/2009 : 19:23:40

Keep the keel down whenever underway, if you do run aground, as said, click it up until you get into more water, then put it back down.

Edited by - on

Dave Bristle
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Djibouti
10005 Posts

Response Posted - 12/20/2009 : 20:01:44

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by jerlim
 Keep the keel down whenever underway...<hr height="1" noshade id="quote"></blockquote id="quote">I didn't own a swinger (I had a fin), but I've sailed a lot of boats for a lot of years and watched the debates here for a decade or so, and I would strongly agree. The cable attachment--the weak point in the system--is under water up or down. A free-fall (due to a break in the cable or its attachment) can be catastrophic. And the designed balance of the boat is based on the keel being down.

Edited by - on

Dave5041
Former Mainsheet Editor

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Response Posted - 12/20/2009 : 20:03:31

I would keep it down for several reasons. You will have somewhat improved stability, the ability to raise it if you should run aground, and , most importantly, the length of the raised keel and reduced bite on the water results in very sluggish response to the rudder.

Edited by - on

pfduffy
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Response Posted - 12/20/2009 : 20:32:44

I've only owned my boat for a year, so please take this with a grain of salt. The channel I motor out of requires me to keep the keel raised. With the keel up, the weight is more aft so the stern rides deeper in the water. In my case, I need to be careful in the channel that leads to the bay. In rough weather, I need to make sure I don't swamp the motor. I add this issue to the others raised above.

Edited by - on

NCBrew
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Response Posted - 12/20/2009 : 21:01:24

Thanks for all the quick answers. Goes to show there are a lot of members reading and responding to the forum.

After weighing all the reply's I think I will travel with the keel down.

It is 11:00 pm and I must get to bed.

NCBrew

Edited by - on

Dave Bristle
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Djibouti
10005 Posts

Response Posted - 12/21/2009 : 07:48:52

Safe journey.

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frog0911
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Response Posted - 12/21/2009 : 09:00:40

If you leave it up and the cable happens to release the boat will sink if you are not there to pull it to shore. That is how the original Pretty Penny, a 1979 C25, ended up with a wing keel and a new motor. So leave it down except when absolutely necessary.

Edited by - on

Ed Cassidy
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Response Posted - 12/21/2009 : 09:33:09

I think this keel thing could (will) go on forever! If the keel is down and you hit a submerged log at hull speed and the keel then drops after clearing the obstruction, wouldn't that have the same effect as the cable breaking? If the keel is half way down (under tension) and the same thing happens, won't the force on the keel cable be far more likely to snap it than leaving it up? One final question. Is it recommended (for speed) to raise the keel when going downwind? Is that because of the drag? Curious minds want to know!
Thanks,
Ed

Edited by - on

Steve Milby
Past Commodore

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Response Posted - 12/21/2009 : 11:05:12

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Ed Cassidy
 I think this keel thing could (will) go on forever! If the keel is down and you hit a submerged log at hull speed and the keel then drops after clearing the obstruction, wouldn't that have the same effect as the cable breaking? If the keel is half way down (under tension) and the same thing happens, won't the force on the keel cable be far more likely to snap it than leaving it up?<hr height="1" noshade id="quote"></blockquote id="quote">

I don't think anyone can answer those questions without engaging in speculation. If any sailboat, regardless of whether it has a swing keel or fixed keel, experiences a hard grounding at hull speed, it's likely to suffer serious structural damage. The difference here is that, if the keel cable snaps while the keel is fully retracted, the common result is that it will cause serious structural damage, and very possibly sink the boat, regardless of whether it's under way and two miles offshore, or in it's slip, and this result can happen without warning and without hitting anything at all. (I had forgotten, but Frog reminds us that that very thing happened to his previous boat, a 1979 C25 swing keel.)

The C25 swing keel is a 1500 lb. chunk of cast iron, that is attached to the fiberglass hull primarily by a single pin and a steel cable. It's amazing to me that early swingers have withstood those stresses as well as they have for 30 years.

<blockquote id="quote">quote:<hr height="1" noshade id="quote"> One final question. Is it recommended (for speed) to raise the keel when going downwind? Is that because of the drag? <hr height="1" noshade id="quote"></blockquote id="quote">

Think about all the different types of retracting keels. When a daggerboard is retracted, it is pulled up into a centerboard trunk. As a result, part of it is actually pulled up out of the water. That means the amount of wetted surface is reduced. If wetted surface is reduced, drag is reduced. Thus, a boat such as a Force 5 or Laser is aided by raising the daggerboard downwind.

When you raise the C25 swing keel, it isn't raised into a centerboard trunk and out of the water, so you haven't reduced the amount of wetted surface. All you have done is to change the orientation of the keel. Some might say that you have reduced drag by reducing the area of the leading edge of the keel that is exposed to the flow of water. Personally, I doubt that makes a meaningful difference, because the keel's shape is designed to be most efficient when the keel is down. When the keel is retracted, a part of the keel is exposed to the flow of water that is not an efficiently shaped foil.

As I said earlier, I experimented with raising and lowering the swing keel downwind on my friends' boats, and never detected a significant difference between the C25 swing keel up or down. I know other good, experienced sailors will disagree, but after experimentation, I didn't detect any difference, and if you think about the effect that raising the keel has on drag, there's no apparent logical reason why it should make a significant difference. As a long-time racer, I'll do anything I think will make the boat go faster, but I won't waste my time and energy doing something of dubious value, because, while you're wasting your time and energy doing that, you could be focussing on other things that are more likely to be productive.

Edited by - Steve Milby on 12/21/2009 11:15:25

Dave Bristle
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Djibouti
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Response Posted - 12/21/2009 : 14:05:15

To add to Steve's comments (with which I agree), I suspect the class racing rules disallow raising the keel. But to me, the overriding issue is safety... Even a racer might, in the frenzy of preparing to round a downwind mark, forget to lower the keel. I don't know the exact stability of the C-25 SK with the keel up, but I can guarantee it's markedly less than with it down. A capsize could be the result, and once she's over on her side, the keel isn't going to want to extend itself to help right her.

Edited by - Dave Bristle on 12/21/2009 14:06:43

Dave5041
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Response Posted - 12/21/2009 : 19:56:29

Actually, there is a logical reason for drag to be reduced. The portion of the keel that is in the trunk is not exposed to water flow (surface drag), and it doesn't mater whether it is the surface or the water that is moving.. That is what wetted surface is; it is not just being wet. The reason that you haven't seen a significant impact on speed is that there probably isn't much difference in drag. I imagine that the turbulence created by the slot is enough to make the change in the keel's surface drag insignificant - you probably only reduce the exposed surface by 20% or so and add a shorter, but blunt, leading edge. Different hull shapes and displacements play by different rules

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andypavo
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Response Posted - 12/22/2009 : 06:50:32

Drag Schmag. Leave that thing down. Only raise it to put it on a trailer or scoot over a sandbar. If you raise it just a little, it puts stress on the cable and that thing will start singing and driving you nuts. I've run aground plenty and never hurt the boat. I'm a terrible sailor. I ran over a sailboarder once. I had the right of way so I ran his ass over.

Edited by - on

Dave Bristle
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Djibouti
10005 Posts

Response Posted - 12/22/2009 : 07:38:25

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by andypavo
 I'm a terrible sailor. I ran over a sailboarder once. I had the right of way so I ran his ass over.<hr height="1" noshade id="quote"></blockquote id="quote">You're right about one thing, and were at fault for the other.

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DaveR
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Response Posted - 12/22/2009 : 10:00:26

I wonder how quickly the density of water increases relative to depth?

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TractorJohn
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Response Posted - 12/22/2009 : 13:10:51

Lots of good info here, I actually checked with my gps in a half*** way and decided I gained 1/2 mph with keel up under power. More importantly with four swingers to my credit so far, I have several times forgot the keel was up and later experienced confusion with side slip or stability until realizing I was depending on the keel being down. Two times I can remember I've actually been in peril with keel up. I think your setting yourself up for a bad day of sailing if you don't practice smart habits. Keep the keel down or you may be to blame for something and they will write about you on this forum.
TJ

Edited by - on

jerlim
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Response Posted - 12/22/2009 : 14:04:16

well said Dave...

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OJ
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Response Posted - 12/22/2009 : 14:36:40

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by andypavo
 . . . I ran over a sailboarder once. I had the right of way so I ran his ass over . . .
<hr height="1" noshade id="quote"></blockquote id="quote">
My boss creamed a sailboarder one year . . . I rewarded him with a sailboarder decal to paste on the side of his coaming!

Edited by - OJ on 12/22/2009 14:37:16

delliottg
Former Mainsheet C250 Tech Editor

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Response Posted - 12/22/2009 : 15:00:36

<blockquote id="quote">quote:<hr height="1" noshade id="quote">I wonder how quickly the density of water increases relative to depth?<hr height="1" noshade id="quote"></blockquote id="quote">

Click on the photo for more info.

[url="http://www.windows.ucar.edu/tour/link=/earth/Water/density.html&edu=high"]

[/url]

Edited by - on

Dave5041
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Response Posted - 12/22/2009 : 17:18:40

Hmmm. So a thousand pound bulb on the end of a thousand foot keel would weight three pounds less than one on a five foot keel and have a little more drag.

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NCBrew
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Response Posted - 12/22/2009 : 18:14:55

I just finished the first half of my trip. Left Hampton, VA passed ICW "Mile 0" (Waterside, Norfolk, VA) and continued down the Dismal Swamp Canal leg of the ICW. Finished at Elizabeth City, NC. About 98 miles.

Is there a place I can set up the photos of the trip?

As for the "Keel up/ Keel down". I can attest to the fact that my boat goes 5.0 MPH with the keel down and 5.6 mph with the keel up. As per my Hummingbird GPS. I have found this to be very accurate.

But.....

I feel better with the keel down especially on a 1977 model Catalina 25 when I have no history of when maintenance was done on the cable or fittings.

I checked with the Elizabeth City shipyard and they charge $8.00 per foot to haul the boat. Then $75.00 to block it up so I can work on it. I am going to order a new cable and fittings. I assume I can get that from CD? If not, does anyone know where I can get one?

New subject...I ordered the window repair kit from CD. I am soon to order the mast to cockpit kit.

NCBrew

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