retractable keel question

[Jon D]

WE have a centerboard on the Moody that is controlled by hydraulics. In the 6 years we have had her no real issues, just maintenance of the glads etc. The keel really makes a difference going to weather and off the wind or motoring when we lift the keel up we pick up a good 3/4 of knot plus.

The system is more complex than a fin but the flexibility comes in handy -- we draw 5'3" board up and 9' down so it is a significant effect. Also the keel is 1,000 lbs of weight that moves down so that increases righting moment a tad.

[swagman]

Originally Posted by roverhi

Only if going hard to weather does a fixed keel boat have a an advantage. Even then it may not be so much if Ted Hoods Robins are any indication. Off the wind, the reduced form drag and wetted surface of a C/B or lift keel boat comes into it's own. Yes you do give up some stiffness but it's not as critical once you crack off. I've got a P35 that is fairly new to me so don't have a ton of experience with it. On impromptu contests she seems to point almost as high as the deep keel boats but is faster off the wind.

After more than 10,000 miles of ocean sailing, windward performance doesn't really mean squat. Hard on the wind is very uncomfortable, hard on the boat, sails and equipment and not very fast in the typical ocean swells. Not something that you do for day in/day out sailing. Only the racers are crazy enough to do it and they usually don't do it for more than an hour or two. Long distance ocean races like the Bermuda and Transpac are mostly reaches or surfing runs so the advantage of a deep keel isn't all that big. The ultra short bulbed keels aren't giving away a lot on wetted surface. Unfortunately, they don't seem to be ready for prime time judging by the number that are resting on the bottom after departing the hull.

Aloha
Peter O.

Hi Peter,
There is no doubt there are some swing keel yachts that are faster than other designs of fixed keel yachts. But IMHO I do not believe any single yacht (and certainly not the Adams 40) can be found where a swing keel version is equal or faster than its fixed keel sister.
I remain open to be convinced otherwise if anyone can direct me towards the evidence.
Cheers
JOHN

[Murray]

Hi Efraim (or anybody else),

Exactly what are those pigs nuzzling up to? (Photo on page 1of this thread) She's dang purdy!

Murray

[Efraim]

That there is a Meadow Lark, designed by L.F. Herreshoff. It was originally designed as a 32ft boat., the one in the pic is 38ft build by Alan Vaitses. There have been several variances on the design over the years.
The admiral and I are in the process of trying to decide on a acceptable cruising boat, we are looking at all options. We are not limiting ourselves to whoever has the largest marking budget.


P.S.The pictures were given to me by a friend, I have no idea where they were taken, but it does look nice!

[johngfoster]

Which are the better types of designs--swing keel vs lift keel? How do the newer van de Stadt lift keel designs compare?

[Alan Wheeler]

It depends on the complexity of either. Lift has always tended to be a little more cumbersome as the keel has to lift up into the cabin space. A swing keel can lift up into the bilge area and no impact at all on the cabin space. But it does come down to design. Another plus is that of impact. I have heard of the odd story of a swing keel doing exactly that when running aground.
All in all, either allow you to get into places a fixed may not. But both add complexity and maintenance, with usually the lifting keel offering the greatest complexity. Depends on boat size and design and just how the lifting and swinging is done of course.

[Steve Pope]

I have a Trismus 37 that has 2 swing keels one amidships and a smaller one aft. With Both keels up we draw just under a metre,boards down 2 metres. They are unballasted 20mm alluminium plate so do not affect the stability of the yacht. Easily withdrawn when the yacht is lifted out for antifouling / maintenance and can with a bit of planning be taken out while in the water. The main has its own winch ratchet type next to the centre board case, the case also acts as a back brace for the cook in the galley. The aft board has a 4 part block and tackle to raise and lower it.(easy) It is generally only used down wind. I use 6mm Dyneema on both lifting systems, none of the sprags that you used to get from ss wire.
The main is used on the wind, (and when manouvering in confined waters,) it can be progresively raised after that, often completely raised once the sheets are freed. I love it, the only negative is having to go below to raise or lower the main board, but so far not negative enough to alter it.
If your French is OK, or you enjoy reading French to English translations google Trismus Populus for the Trismus web page. There are at least 130 of them out there some in GRP, some alloy, and other building material. Very popular in the 80's. Mine has been most of the way around the world and still going strong.

[Steve Rust]

I have always liked the French built Ovni line. It was good enough for Jimmy Cornell to sail to all parts of the globe. Would be my number one choice if I was looking for a monohull. For me shallow draft is an important attribute for a cruising boat.

[roverhi]

I don't know about the Van de Stadt design but the problem with lifting keels, essentially ballasted dagger boards, is the weight and support structure. With the typical pivoting center board, you are talking a fairly light board that uses good old Archimedes principles to make lifting easier. Instead of trying to lift a very heavy keel vertically, you are using a tackle of some kind to swing a board around a pivoting pin at one end and force multiplier lifting moment arm somewhere along the board. The farther the tackle is attached from the pivot, the less force required to raise. The centerboard is also almost housed entirely in the keel below the cabin sole.

The pivoting centerboard is less prone to damage than a lifting keel. In the event of grounding, the centerboard would hopefully pivot into its housing. Heard of more than one boat owner who use their center board as a depth sounder. Of course, the board could be and has been bent on grounding. Still, a ballasted boat with a lost center board will still stay upright and sail quite well without the board.

Lifting keels suffer from the engineering needed to support the very heavy weight of the keel in the down position and the energy needed to lift it. The support for the keel has to be to very close tolerances to prevent flutter and wobble of the keel underway. That is a problem in a grounding as even the smallest bend in the keel will either prevent it from being raised or wedge it in some intermdiate position. The Hobie 33 is an example of the problems with these lift keels. Many of them have permanently locked their keels in the down position because of problems with the lifting mechanism. Most others do not raise the keel except to get them on a trailer. As far as sailing ability, the lifting keel has it all over a center board, however. You have the short, deep, hydrodynamically efficient fin with a bulb of the latest hotrod boats with the ability to raise it for less drag off the wind and getting into thin water. Unfortunately, the reality hasn't been as wonderful as the potential when it comes to raising the keel. As some one else has mentioned, there is also the intrusion of the lifting keel support system into the living quarters of the boat. Not a big deal for the racer who only goes below to sleep but not for the cruising sailor who has this large impediment smack dead in the center of the boat.

Aloha
Peter O.

[Therapy]

Originally Posted by jennygail

I'm new to this forum. I've been looking at different sites that have sailboats for sale, what are the pros and cons of having a retractable keel? Is this pretty much only to get in shallow water??

Much has to do with the size of the boat.
I had a 18 ft Westerly Nimrod for a while. We sailed and camped with it on the West coast of Florida which is rather shallow and featureless. The ability to raise the keel and cut across great swatches of shallow water cut miles off of sailing legs. Sailing close hauled at 4 knots with 2 knots of leeway makes for an interesing chart plot. Anchoring where other boats could not run (1 ft sometimes) made it easy to sleep.

I introduced my now-wife to the boat and spent a good part of the day in the Gulf and headed in later than I should have. It was at least 2 hrs to the anchorage, maybe 3. Coming in the pass I noticed a small channel about 2-3 ft deep winding through a flat and then through a dune right to the area of the anchorage. The cut was not on the chart because it had been cut by a hurricane a year or two earlier. With the last of the sea breeze, against the tide I wiggled through that in time for the sunset.......and after that........well ummmm

Maybe that is why I like swing keels.....some sort of primitive associaton.......Hmmm.

Small is probably better, but I may well end up with a Gemini, partly for the ability to stop in shallow places. Last night I was looking at a chart of a place I dream of visiting again and I noticed a lot of small areas to anchor but only if one drew 3 ft or less. Lots of them. I think Florida and Bahama-use make it a very attractive idea.

[sandy daugherty]

My 2'10" draft means that My Chesapeake Bay is a lot larger that someone else's, but my sub-optimal pointing ability means its a chore to tack back up the river to my pier. That's why I keep that lottery ticket under my pillow, for a daggerboard cat! (and a spare board.)

[svquest2]

The Hobie 33 has a tightly fitting retractable keel that is kept locked down when sailing or racing, and it has a short trunk with a cover inside the salon. The keel is raised to put the boat on its adjustable trailer, or the boat can be lifted on the high trailer adjustment with the keel down for painting or maintenance. It's also a very quick racer.

[Tempest245]

I have owned 2 Centerboard vessels, a Bristol 29.9 and my current Sabre 34.

As Paul and others have mentioned, how you view a CB largely depends on where you sail. I sailed on Barnaget Bay N.J. for many years where even with a 3.5 board up draft, I could easily bump bottom. I'm in the deeper waters of Raritan bay now, but other vessels in my marina with much deeper drafts than my current 4' must wait for the right tide to enter and leave. Temopest spent 10 years on the chesapeake where having the shoal draft extended her access as well.

The only annoying feature that I could point out, is that the board makes a little bit of a racket in it's slot in a following sea when it's retracted.

Tempest.

[Suncruiser]

I am looking to purchase a yacht to cruise of the West Coast of Canada.
I am looking to fit comfortably 4-6 people in the cabin.
Also, my preference would be to tow it behind my track, however this is not a must.
I am quite novice in this area, although I have some sailing experience, mostly in Europe on the Baltic Sea.
Can you give me any recommendations?
Do I need a retractable keel or a swing keel for these waters?

[migot1]

we have a SOUTHERLY 115 37ft lifting keel boat==now for 20 years. we can enter shalow ports ,like small fishing harbours, and shalow bays -were nobody can drop anchor. it is wondreful. special.