Need a Precise Explanation

[Paul Annapolis]

I'm confused because the OP owns a Bristol 30 that is apparently a keel/centerboard and then asks a pretty basic question that one would assume she would already knows because she owns such a boat and then asks "What is each function? I know nothing" and later asks "What are the risks? I have this on my Bristol 30' 1971. I"m aiming for offshore cruising eventually. What would I have to do to change this?" What would I have to do to change this? Seriously? You'd have to buy a different boat! Well, you could haul the boat, spend more money than the boat would ever be worth and do a massive, difficult and complex modification..and that's just for starters. Other folks have noted that there are many fine cruising boats with keel-centerboards that have done a great deal of serious cruising-and then start to get into some of the usual back and forth online debate about relative merits or disadvantages. But why post such a simple question about a 45 year old boat you already own that you could quite easily look up online or in any basic book about sailing? But then to ask what would it take to modify it? It would be like owning your own Boeing 737, asking what is a fuselage and then asking what would it take to turn it into an Airbus 320.

[SkiprJohn]

Originally Posted by zengirl

Exactly what is a shoal keel with centerboard? What is each function? I know nothing Thanks for your usual expert help.

Don't change a thing. They are perfectly great boats so all you have to do is make certain you can raise and lower your centerboard. Many sailors leave them in one place and just sail around inefficiently. You need to learn that when you are sailing to weather you want the board down unless the water is very shallow. When going downwind then bring the board up or if you are lazy and don't mind going as slow as many other 30s leave it down.

Get all those mechanical things working well and you'll have a boat that will go faster downwind tham most 30s and definitely sail better to windward than any shoal draft or wing keel 30.

I repeat, "don't change a thing." Those Herreshoff boys knew what they were doing.

[SkiprJohn]

Originally Posted by Paul Annapolis

I'm confused because the OP owns a Bristol 30 that is apparently a keel/centerboard and then asks a pretty basic question that one would assume she would already knows because she owns such a boat and then asks "What is each function? I know nothing" and later asks "What are the risks? I have this on my Bristol 30' 1971. I"m aiming for offshore cruising eventually. What would I have to do to change this?" What would I have to do to change this? Seriously? You'd have to buy a different boat! Well, you could haul the boat, spend more money than the boat would ever be worth and do a massive, difficult and complex modification..and that's just for starters. Other folks have noted that there are many fine cruising boats with keel-centerboards that have done a great deal of serious cruising-and then start to get into some of the usual back and forth online debate about relative merits or disadvantages. But why post such a simple question about a 45 year old boat you already own that you could quite easily look up online or in any basic book about sailing? But then to ask what would it take to modify it? It would be like owning your own Boeing 737, asking what is a fuselage and then asking what would it take to turn it into an Airbus 320.

Aren't you being a little hard on someone who admits they don't know the anwer and wants to know? I hope you're not an instructor.

[Paul Annapolis]

John I don't think its being harsh. I think it's a dose of reality--or perhaps "tough love" This OP already owns a boat--a keel centerboard boat and asks the good and helpful folks on here to take our time and provide our advice (or simple answers in this case) to answer a very simple question--a basic question about a fundamental and immutable feature of the boat she already owns and then asks what it would take to change it! So many questions are posed on here that could quickly and easily be answered in a basic sailing book or a website. It makes my head swim to wonder if this persona could have already bought a keel centerboard boat and then ask what it is and say she knows nothing--and we are supposed to encourage her to go to sea? Do we not have some responsibility to each other to at least be basically responsible on the water? I certainly could have rolled my eyes and ignored the question. Yes I could have done that. I once placed a newspaper ad selling my pool. I provided the dimenstions and included gear and equipment. One caller asked if it was an in-ground pool or an above-ground pool. Now remember that the OP said she needed "a precise explanation" and I believe I am the only commenter who even touched the q

[Paul Annapolis]

Sorry--to continue--- who even touched the question about modifying the keel. Would it have helped had I been more precise?

[roverhi]

Keel/centerboard boats are just fine offshore, inshore and onshore. Some even say they are better In ultimate survival conditions because they don't have as deep a keel that could trip the boat and cause it to do a 360. Otherwise, they have less leeway resistance so would slide rather than role if sideways in a breaking sea. Don't think i'll volunteer to test out that theory, however.

A true centerboarder will have more hull form stability, flatter bilges, to compensate for the shallower ballast ratio. Often they will have a higher ballast displacement ratio to increase heeling resistance. Some boats like the Bristol 35 and 39/40 were the same hull but the keels were just shallower. They still seem to sail well. Most others like my Pearson 35, 39, 40, Morgan's C/B boats, Bristol 35.5 and other '*.5' boats, Hood's boats, Tartan 27, 34, and 38 and the French alloy C/B boats were all designed from the bottom up as center boarders. Many have circumnavigated and sailed to extreme high latitudes without issues.

One thing a center border doesn't have is a deep keel to drag around when it has no advantage. Once you crack off the wind, a deep keel has little advantage and the disadvantage of dragging around additional wetted surface. Have owned and currently own a keel/C/B boat. Seldom feel the necessity to use the board and couldn't tell you if it really does that much good. Sure it decreases leeway hard on the wind but, for me, not enough to make a night or day decision. As far as maintenance, it really isn't much. You do have hang in the slings over night to paint it the night before launch. If you have a metal cable, it may need to be changed out occasionally. Changed the galvanized cable on my current boat after six years, it could have easily gone another couple of years. Changing the cable took less than an hour and that mostly because it was the first time I'd done it on this boat. Hopefully will never have to do it again as I changed to a synthetic cable which won't have the corrosion issues of wire. Maintenance is a hell of a lot less than dropping a bolt on keel to check the bolts that have lived in yucky bilge water their whole life.

Just to be sure, I'm tallking keel/centerboard not swing keel, drop keel, etc. These boats go from unsafe in a seaway to way too complicated for the average cruiser. In a keel centerboard the stability is in the keel. The centerboard is there for leeway in very limited situations. Whether the centerboard is there or not, they sail just fine.

As a last comment, Adlard Coles in 'Heavy Weather Sailing' marks the loss of a C./B boat in a hurricane as a reason to stay away from them. Somehow, the single loss of a boat with no record of the circumstances in a hurricane seems to carry little weight as to the suitability for offshore work.

[El Pinguino]

Ovnis Ovni range, Alubat | Alubat form a large percentage of the yachts passing through Chilean Patagonia each year... just saying.....

[canyonbat]

Originally Posted by SkiprJohn

Aren't you being a little hard on someone who admits they don't know the anwer and wants to know? I hope you're not an instructor.

I am with John on this one. First, you assume she bought the boat. Maybe she inherited it from a loved one and wants to use it rather than sell it. Second, why should someone start the research process by reading a book rather than ask a quick question to give them an idea of what book to read? I think berating someone for asking a question shows arrogance and is in poor taste. Everyone starts the learning process somewhere.

[ob44]

I guess the nom de plume, COBG, is appropriate. The Tartan 40 is a shoal keel CB boat. In its day, it was a very popular offshore racer/cruiser and now is a very popular ocean cruiser. The Sabre 38 MK II is another example of a blue water CB boat. The superstition that CB boats are inherently less stable is just that.

[Greenhand]

Originally Posted by El Pinguino

Ovnis Ovni range, Alubat | Alubat form a large percentage of the yachts passing through Chilean Patagonia each year... just saying.....

Which is funny because down Patagonia way OVNI stands for UFO.

[rhubstuff]

Back in the old CCA rule days, centerboard boats were commonly raced all over the world in the toughest conditions. Seaworthiness is just as much a function of seamanship as stability. Know your boat. Know what she can take and how to sail her well and safely. As for shallow draft, I've found that I run aground as much or more with shallow draft than deep, because I'm always saying "Sure, we can get in there. No problem." Oops.

[Cheechako]

There's nothing wrong with a good Keel/centerboard for offshore sailing. Is your boat tender now? or stands up to strong winds well?

[Bulawayo]

I understand your concerns but there many off-shore yachts of this cofiguration. We have a French friend who sails a 54 mono-hull that fits this description - he has circumnavigated too many times to recall, in all weathers.

[zengirl]

Thanks to all for all the great info. Paul Annapolis, to clear up your confusion, I have never seen my boat. I am in Midland, Tx and my boat is in Brandon, Ct. She won't be in the water until May of next year. "what can i do to change this" was a stupid question. Agreed.
I was fine with the whole setup until I read something negative about it. Got paranoid and got on here to get the real scoop. I have read and read about shoal keel centerboards and the info I got here is tops compared to what's in the books. Don't worry (I know you won't) about being harsh, I'm a tough cookie and thanks again for all the input.

[hamburking]

I had a Paceship 29 with swing keel (keel centreboard if you like).
It had a substantial shallow keel, longer and heavier than the regular fin version. A slot in the centre fitted with a heavy centreboard which rotated on pin forward. The centreboard extended aft of the keel when up. A simple SS cable raised/lowered the board, with a winch mounted on the bridgedeck in the cockpit.

Generally, I left the board UP most of the time and enjoyed the extremely shallow draft. The extra weight made up for the lack of cantilever (depth). The boat was very stable. The only time I needed the board was when close to the wind for an extended time. It improved performance, but only a little. To be honest, in general it wasn't a good sailing boat, but I think that had little to do with the keel, and more to do with my tired old sails.

I really miss the shallow draft, I could go anywhere, it drew about 3.5'. My new ride, a Pearson 30, draws 5', and I have bumped a few rocks.

In heavy seas the board tends to bang around in the slot. There is always concern of the pin breaking, or the cable breaking, since both are underwater and not available for inspection. However, having said that, my boat was about 40 years old, and the board never gave me a lick of trouble.

I have heard of Tanzer 22s with the swing keel getting stuck. Apparently they were made of cast iron. When they corroded, they also expanded. Trouble.