To bilge keel or not to.

[Sneaky Pete]

Back on the yacht market for another sail boat after a short absence. Looking for 2 cabin version sloop about 36+ feet. Noticed a few bilge Keeler's on the market. My question is if there is the same make and model of sail boat, one is fin keel the other bilge which would you buy, and why.
I haven't sailed a bilge Keeler so do not know the different characteristics of such a boat, and the plus and minus of this set up. My only knowledge is they can be dried out on a shore and less draught.

 

[westernman]

Back on the yacht market for another sail boat after a short absence. Looking for 2 cabin version sloop about 36+ feet. Noticed a few bilge Keeler's on the market. My question is if there is the same make and model of sail boat, one is fin keel the other bilge which would you buy, and why.
I haven't sailed a bilge Keeler so do not know the different characteristics of such a boat, and the plus and minus of this set up. My only knowledge is they can be dried out on a shore and less draught.

A bilge keeler doesn't go to windward as well as a fin keeler. Otherwise very little difference on other points of sail.
Real gentlemen don't sail to windward anyway.....

 

[B27]

36+ feet is not the 'run of the mill' bilge keel yacht.

I'd buy a deep fin if I had a deep mooring lined up and facilities to scrub and a desire to race or sail a long way to deep harbours. I'd buy shoal draft if that matched my plans better.

Look at it in the round.
If I buy X what will I do in the next 5 years?

I'd be happy to swap my bilge keel boat for a fin or a multihull for the next 5 years if I had a plan to get fair use out of it at a reasonable cost.

 

[Concerto]

Hunter Legend are the only brand that springs to my mind who built 36ft bilge keel yachts as normal production boats. I believe the main reason is the strength required in the hull/keel structure for regular drying out as the overall size and weight of a 36ft yacht did not have sufficient buyers willing to pay the surcharge for the bilge version. Generally 34ft seemed to be the limit most manufacturers stopped offering bilge keels.

I sail a fin keeled 32ft Westerly Fulmar and the twin keeled version actually sold slightly more than the fin version. The Fulmar was designed in 1979 as a fin keeled boat, but customer pressure in 1980 made Westerly have moulds made for a twin keeled version. I have only sailed against a twin keel Fulmar on a couple of occassions and I sailed away very easily, part could be due to my folding propeller. The folding propeller does make a large difference as I have also sailed against a fin keel Fulmar with a fixed bladed propeller, again I sailed away.

Once you reach 34ft, most owners prefer to keep their boats in deep water moorings/berths. My choice is always keep a boat afloat as there have been many occassions where bilge keels have failed due to regular grounding with every tide (some Westerly models included). These failures have all been due to the evolution of using the relatively new material in the 1970's and 80's called GRP. No amount of testing is the same as having boats being put in those situations. Some keels failed due to repeated grounding on hard ground, others due to the suction of mud on the keels stopping the boat from lifting with the tide. Virtually all the classes where there has been a failure will have had by now major remedial work to strenthen the hull/keel area.

On a slightly different tack, larger boats sail faster so the cruising range is extended. A friend used to have a 30ft boat and changed to a 40ft boat believing he would continue to sail in the same way. This increased range gave him a wider choice of harbours to sail to in a day, so he could ignore the nearer drying harbours and creeks. Presumably Sneaky Pete, you are moving up the size range of boat, so this situation will probably apply to you as well.

If you are wanting a large boat to go ditch crawling or drying out, then a full lift keel like a Southerly, should be on your list of boats to consider.

 

[alan_d]

It is horses for courses.
Although I sail on the west coast of Scotland and shoal draft would be unnecessary, my home mooring is some forty miles from the nearest lift-out facility. I therefore decided that the ability to dry out easily might be an advantage ( I have some sheltered drying sand close to my mooring). Accordingly I bought a (bilge-keeled) Westerly Konsort, which I have had for the past sixteen years and am very happy with. It sails well enough for my single-handed pottering around the Inner Hebrides and I have twice made use of its ability to dry out, once to remove a rope from around the propellor and once to clear crustaceans from the water inlet for the heads.
Someone else with different needs and priorities might well decide that a deep-keeled boat would suit them better.

 

[Stemar]

I've no experience of bigger twin-keeled boats, other than a few comments from owners about Hunter Legends which don't make me want one, but being able to tuck into a shallower part of the anchorage or harbour and dry out opens all sorts of possibilities denied to those who must stay afloat. As for performance, I reckon a bilge keeler sailed well will do better than an equivalent fin sailed poorly. Add a folding prop and you'll do as well as most equivalent fins.

Don't RM yachts have twin keels? Now there's a decent boat that goes well.

 

[johnalison]

If you are sailing from marina to marina or anchorage, there will be no point in putting up with the disadvantages of bilge keels, even if these are not important to some sailors. If you need a shallow mooring or wish to dry out, bilge keels are a good option for anyone not wanting lifting or swing keel. There have been a few times when drying out seemed very attractive. There is a shallow bay on Bryer where a boat dried out could happily sit out a passing storm while we finners had to scuttle for shelter, but for me the advantages of a fin are not insignificant.

 

[ProDave]

We chose bilge because of where we keep the boat, in a drying harbour. In point of fact the actual berth we are in does not dry out but the access to it does. If we had chosen a fin keel then we would be limited to a much more expensive marina, or a more exposed than i would like mooring.

We don't routinely dry out, but it is quite reassuring that if we did, she would remain upright.

At crane out time all we need is some planks of wood for the keels to sit on. A fin keel would require you to own or rent a cradle.

If you have a deep water berth and don't plan on ever visiting somewhere that dries out, and are confident in your navigation that you won't dry out by mistake, then choose a fin feel. But not four us.

Re a fin sailing faster than an otherwise identical bilge keel, too many variables. We were sailing in company with an identical boat to ours, same keels, in light winds and we were sailing faster. We could not work out why, in theory the other boat should have been faster as he has newer sails. So a one off comparison is meaningless. In any event if racing, the handicap should null the difference in performance.

 

[johnalison]

I think there is too much information about bilge keels pointing less well or sailing less well to windward for it to be dismissed as an urban legend. I tend to think of it as a ball-park figure of five degrees off the wind when close-hauled. One could compensate for this by having a well set-up boat and good sails, such as a laminate jib.

 

[Tranona]

As said very few twin keel boats above 34' and apart from Legends and RMs none are "modern". So your choice is very limited. If draft is an issue then there is a much better choice if you go lifting keel. Many boats of this size have only 1,5m, particularly the older heavily ballasted types which do not need the deep draft that modern fin keelers tend to have. Most of the pros and cons have been discussed. My view having owned one bilge keel, 2 triple keel and 2 shallow draft fin keel is to go fin keel every time, preferably deep. My first fin (37') was shallow because the plan was to go through the French canals and the second because it did potentially extend the area of usage of the boat based in Poole. My current boat is a triple keel, but is an oddity and good for drying out as well as hauling and storing ashore. I have a deep water marina berth and TBH would not want to keep on a drying mooring having seen the potential dmage for doing this long term except maybe in soft mud. Over 5 tonnes dropping onto a hard seabed twice a day is not a good idea.

 

[dunedin]

As said very few twin keel boats above 34' and apart from Legends and RMs none are "modern". ….

Sirius are an exception, who make modern pilot house bilge keelers at larger sizes … but also at a serious price.

 

[RogerJolly]

It's said the aerofoil shape of keels provides lift.

Can see that working for an aeroplane wing where it can be asymmetrical, so the top surface shape pulls upwards more than then bottom shape pulls downwards. But a boat keel is symmetrical or it would only work well on one tack. So how does that work?

With twin keels we have an 'upper' keel and a 'lower' keel, so we're back to asymmetry and we can play with splaying and toeing in, to maybe equal or beat fins?

 

[jwilson]

Moodys made a few 36s up to the early 2000s with twin keels. When they come up for sale they often tend to sell very fast - tells you something. Well designed twin keels don't lose that much to fin-keelers to windward, but there are not many around that have deepish well designed twin keels. The Sadler 290 was one - designed to have fin or twin keels, but of the 50 or so built almost every one was twin keel.

But many older twin keelers are pretty poor to windward.

 

[Sandy]

My last boat a Mirage 28, bilge keeled, and my current boat Gib'Sea 96, fin keeled, are like chalk and cheese. I pointed at 50° to the wind I now point at 25° to the wind. Oddly, only once dried out in the Mirage 28 due to the local mussel farm seeding the river while I was on holiday and I needed to scrape lots and lots of tiny mussels off the prop.

Fin keel wins every time.

 

[benjenbav]

With a lift keel, would it be best to moor with keel part down? Assuming neither a deep water nor a drying mooring.

Thinking about movement around a mooring buoy in relation to neighbouring boats and also roll, to a lesser extent.

 

[johnalison]

With twin keels we have an 'upper' keel and a 'lower' keel, so we're back to asymmetry and we can play with splaying and toeing in, to maybe equal or beat fins?

I'm pretty sure that it has been tried, possibly by Snapdragon. I believe that the toe-in itself increases resistance and negates any advantage. Perhaps if you designed a boat such that the windward keel would soon lift itself clear of the water you could be onto a winner, or more likely not.

 

[srm]

Back on the yacht market for another sail boat after a short absence. Looking for 2 cabin version sloop about 36+ feet. Noticed a few bilge Keeler's on the market. My question is if there is the same make and model of sail boat, one is fin keel the other bilge which would you buy, and why.
I haven't sailed a bilge Keeler so do not know the different characteristics of such a boat, and the plus and minus of this set up. My only knowledge is they can be dried out on a shore and less draught.

To avoid repetition you may find this recent thread of interest, or at least some parts of it.

Bilge keel draught when heeled

To answer the question, the only twin keel yachts I have bought were two catamarans. The three monohulls all had a deep longish keel with keel hung rudders and by modern standards narrow beams. But, they suited my style of cruising and the waters I chose to sail in very well.

 

[Thresher]

Back on the yacht market for another sail boat after a short absence. Looking for 2 cabin version sloop about 36+ feet. Noticed a few bilge Keeler's on the market. My question is if there is the same make and model of sail boat, one is fin keel the other bilge which would you buy, and why.
I haven't sailed a bilge Keeler so do not know the different characteristics of such a boat, and the plus and minus of this set up. My only knowledge is they can be dried out on a shore and less draught.

I've had my twin keeler for over 20 years and have probably dried out only half a dozen times in that time. For me the benefit of having twin keels hasn't outweighed the disadvantage of not being able to point as well as I would like. Unless you know for sure that you will be using those twin keels a lot then I would go for a single keel. Scraping, scrubbing and antifouling between those twin keels is no fun either.

 

[John_Silver]

To put some numbers on the Fin v's Bilge performance difference, here is data from Fora Marine. The tables show VPP numbers for their RM1070+. A modern 35 footer which is available in Bilge keel (Biquille), Fin (Monoquille) and lift keel (Quille Relevable) configurations. The bilge keels in question are bulbed, high aspect designs. The third table gives the %age difference in performance, between the fin/ lift keel (first table) and bilge keel (second table) versions, over the full range of wind angles and strengths. The performance of the lift keel and fixed fin are said to be identical. Broadly, the lighter the wind and the tighter its angle, the greater the advantage of the fin(s). 10%, at its height. Diminishing to 0% as the breeze comes onto, and aft of, the beam.
The RM range starts at 30 feet and goes up to 45. All models available with fin, lift or bilge keels.

 

[Gsailor]

It has all been said in the above posts - with lots of excellent, well honed advice, I have nothing to add unless you provide more info as to your sailing area or mooring or whatever.

I have owned fin and bilge keel. The phrase, horses for courses does count- even if Chay Blyth tried to sail a bilge keeler around the world in the Golden Globe - he turned back of course - but went on to achieve a lot in other areas of sailing.

Has anyone mentioned lifting wing keel? Possibly out of range.