G
Guest
Guest
Fin Keel, Bilge Keel, Long Keel ? I know it sounds like a simple issue but as I am looking to buy my first boat I would like to to have some idea of the pro's & con's.
chippie
New member
A complex subject, Bilge keels seem best if your boat is to take the ground, but forget windward performance.
Long keels are associated with more traditional hull shapes and can readily take the ground but you will need legs to hold the boat upright. Long keels have a reputation for tracking stability , but due to more wetted area have more drag and therefore inhibit speed. They can also be slower to tack . As their draft is often less than a fin keeler of similar length they tend to be more tender. They offer more protection for the rudder and prop, both from grounding and ropes etc. They tend to be on heavier boats.
A modern , well designed fin keeler can have good tracking ability once 'in the groove' and has the ability to turn sharply and tack quickly.Taking the ground is somewhat more problematic and is usually done against piles or a seawall or the like. The relatively deeper draft may be a problem in your area or not. The rudder will be hung separately either with a skeg to support it or be a spade type that is wholly supported from above.
Unless you are in love with the undoubted charm of older style boats I would recommend a fin keel as these are where yachting has evolved to and have had quite some years of refinement on cruising boats as well as racers.
Long keels are associated with more traditional hull shapes and can readily take the ground but you will need legs to hold the boat upright. Long keels have a reputation for tracking stability , but due to more wetted area have more drag and therefore inhibit speed. They can also be slower to tack . As their draft is often less than a fin keeler of similar length they tend to be more tender. They offer more protection for the rudder and prop, both from grounding and ropes etc. They tend to be on heavier boats.
A modern , well designed fin keeler can have good tracking ability once 'in the groove' and has the ability to turn sharply and tack quickly.Taking the ground is somewhat more problematic and is usually done against piles or a seawall or the like. The relatively deeper draft may be a problem in your area or not. The rudder will be hung separately either with a skeg to support it or be a spade type that is wholly supported from above.
Unless you are in love with the undoubted charm of older style boats I would recommend a fin keel as these are where yachting has evolved to and have had quite some years of refinement on cruising boats as well as racers.
johndf
New member
It depends on what you want from your boat. If you are planning to race then a fin keel is the obvious choice. If you are cruising, then it depends on where and what sort of cruising you plan to do. If you plan to spend most nights in marinas, then a gain a fin may be the best option. If on the other hand you want to be able to dry out on a beach or in a drying harbour, then bilge keels or a lifting keel would be beter, or a long keel but then you'll need to mess about with legs. I think that Chippie has perhaps overstated the lack of windward ability of bilge keelers. They used to be poor at sailing upwind,but modern designs have apparently got over that problem, if reviews are to believed.
I have a shallow fin keel on my boat, but often wish i had the option to dry her out easily. Next time I'm going to look at a lifting keel or bilge if available. Unfortunately this limits ones choice of boat, particularly once you get above thirty feet in length.
I have a shallow fin keel on my boat, but often wish i had the option to dry her out easily. Next time I'm going to look at a lifting keel or bilge if available. Unfortunately this limits ones choice of boat, particularly once you get above thirty feet in length.
G
Guest
Guest
I think it also pays to distinguish between bilge keels and twin keels, too. The original bilge keels were little fins on the bilges, of much the same draft as the main central (ballast) keel. With boats fitted like this, the bilge keels contributed little to controlling leeway, the hull relying on its central keel for that. But as this was deliberately kept shallow to allow access to shoal waters, so it allowed a fair bit of leeway to be made.
There are some photos of my bilge-keeler Sanderling at http://albums.photopoint.com/j/AlbumIndex?u=1231924&a=9316678&f=0 Sanderling draws only 2'-9" - ie about half what a traditional hull of the same size would draw. She's a perfectly good sea-boat, but she makes somewhat more leeway than the traditional single-keeled hull would do.
Later twin keelers have done away with the central ballast keel altogether, replacing it with two ballast keels, one on each bilge. I think it's these that JohnDF talks about when he mentions later designs being more efficient. I think they're still not as efficient as a deep central keel, but somewhat better than Sanderling.
The advantage that all bilge-keelers and twin-keelers share is the priceless one for gunkholers of being able to dry out anywhere, upright.
I think you shouldn't forget that all boats are compromises. The thing to do is to specifiy firstly what are the conditions under which you'll be using her, before deciding on the type of vessel that will best meet those conditions.
mikefield@woodenboatfittings.com
There are some photos of my bilge-keeler Sanderling at http://albums.photopoint.com/j/AlbumIndex?u=1231924&a=9316678&f=0 Sanderling draws only 2'-9" - ie about half what a traditional hull of the same size would draw. She's a perfectly good sea-boat, but she makes somewhat more leeway than the traditional single-keeled hull would do.
Later twin keelers have done away with the central ballast keel altogether, replacing it with two ballast keels, one on each bilge. I think it's these that JohnDF talks about when he mentions later designs being more efficient. I think they're still not as efficient as a deep central keel, but somewhat better than Sanderling.
The advantage that all bilge-keelers and twin-keelers share is the priceless one for gunkholers of being able to dry out anywhere, upright.
I think you shouldn't forget that all boats are compromises. The thing to do is to specifiy firstly what are the conditions under which you'll be using her, before deciding on the type of vessel that will best meet those conditions.
mikefield@woodenboatfittings.com
G
Guest
Guest
Re: Lifting Keels
You mention the idea of lifting keels and I have thought of the Southerly's and their lifting keel but then I think of all that weight on a pin and wonder about and have visions of my keel heading for the bottom. I'm sure it's never happened but what thoughts or experiences has anyone had.
You mention the idea of lifting keels and I have thought of the Southerly's and their lifting keel but then I think of all that weight on a pin and wonder about and have visions of my keel heading for the bottom. I'm sure it's never happened but what thoughts or experiences has anyone had.
vyv_cox
Well-known member
Re: Lifting Keels
I don't know about the Southerly, but the Sadler lifting keel sits on a massive shoulder arrangement when lowered, the contact surface is full breadth of the keel x about three inches each side. No chance it could fail and allow the keel to fall out.
I don't know about the Southerly, but the Sadler lifting keel sits on a massive shoulder arrangement when lowered, the contact surface is full breadth of the keel x about three inches each side. No chance it could fail and allow the keel to fall out.
Grehan
Well-known member
Southerly
Yup, we got one. [Southerly 115]
See . .
http://www.northshore.co.uk/
and then "Archive" and "Owners" from the side menu.
After a season and only limited experience of 'other keels', our impression is that our boat is well-designed, comfortable, well-made and tough, and that the lifting keel is very practical, sound and safe. She sails very well downwind in light airs with the keel up, just like a dinghy. Settles onto the beach gently to dry out. Limited keel 'height' means she's not as manouevrable/responsive as would - might? - be the case with a full deep fin keel (particularly in reverse and in crowded marina situations) - but then we're still learning her little ways. There's an active owner's association.
We're pleased, but has anyone any contrary opinions?
Yup, we got one. [Southerly 115]
See . .
http://www.northshore.co.uk/
and then "Archive" and "Owners" from the side menu.
After a season and only limited experience of 'other keels', our impression is that our boat is well-designed, comfortable, well-made and tough, and that the lifting keel is very practical, sound and safe. She sails very well downwind in light airs with the keel up, just like a dinghy. Settles onto the beach gently to dry out. Limited keel 'height' means she's not as manouevrable/responsive as would - might? - be the case with a full deep fin keel (particularly in reverse and in crowded marina situations) - but then we're still learning her little ways. There's an active owner's association.
We're pleased, but has anyone any contrary opinions?
billmacfarlane
Active member
The lifting keel has been mentioned here but not the centre plate. The 2 shouldn't be confused or thought of as the same thing. A centre plate cofiguration is different as the boat has a fixed stub keel with the plate sitting inside it , the center plate being raised or lowered by lifting gear from either the cockpit or inside the boat. The lifting gear tends to less heavy duty than for a lifting keel , usually just a winch as the plate pivots round a bearing.
Advantages: Shallower draft when you need it. The stub keel tends to fairly long and it's easy to lie alongside a drying harbour wall with the plate up. Windward performance with the plate down can be good.
Disadvantages: Keeping plate clean and antifouled can be a bit of a pain as access is difficult with the boat on hard standing. In some designs the plate moves about in the keel when sailing with a fair bit of noise. Can't take the ground without legs.
Advantages: Shallower draft when you need it. The stub keel tends to fairly long and it's easy to lie alongside a drying harbour wall with the plate up. Windward performance with the plate down can be good.
Disadvantages: Keeping plate clean and antifouled can be a bit of a pain as access is difficult with the boat on hard standing. In some designs the plate moves about in the keel when sailing with a fair bit of noise. Can't take the ground without legs.
Bergman
New member
Re: Lifting Keels
I once looked very closely at the arangement on the Southerly and it appeared as near bomb proof as you can get. I would certainly have no worries about it dropping out.
My Parker 31 has a similar arangement to the Sadler, the keel is fitted in a stainless steel "box" and wedges in position all around. Parkers say the arrangement has been drop tested. It certainly fits very solidly there is absolutely no movement under sail or power and of course it dries out perfectly.
I once looked very closely at the arangement on the Southerly and it appeared as near bomb proof as you can get. I would certainly have no worries about it dropping out.
My Parker 31 has a similar arangement to the Sadler, the keel is fitted in a stainless steel "box" and wedges in position all around. Parkers say the arrangement has been drop tested. It certainly fits very solidly there is absolutely no movement under sail or power and of course it dries out perfectly.
G
Guest
Guest
Further to this, here's a post that I copied from another bb some time ago -- relevant and interesting.
----------------
Three of a kind
Over the Spring Bank Holiday Weekend, the Trident Owners Association held a short 21 mile race "around-the-buoys" in the Solent. All three types of Trident, bilge keel, fin-keel and retractable centre-boarder, were represented. At the end of the race it was not possible to distinguish any advantage or disadvantage to any kind of keel form.
The performance of the boats in the varying conditions during the race appear to be roughly equal. Although there were various changes of position, there was very little difference in time between the first and last boat home (eleven boats took part) considering the length of the course.
We started on a run in light airs, where a centre-boarder with his board up and his outboard motor removed, definitely had an advantage (all the other boats had inboard motors). The most interesting section was a close fetch, hard on the wind in an approximate force 3, when one would have expected the bilge-keel boats to be at a disadvantage, but this was not the case. I wonder if other PBO readers have any experience of other classes which have varying keel forms, where they can show a difference in performance.
It is often said that a bilge-keel is at a disadvantage as against a similar fin-keel boat, and although I must agree that one race might not tell the whole story, I would be interested in the experience of any other classes.
R W TYLER, Trident Owners' Association, 13 Trafalgar Road, Twickenham, Middlesex.
mikefield@woodenboatfittings.com
----------------
Three of a kind
Over the Spring Bank Holiday Weekend, the Trident Owners Association held a short 21 mile race "around-the-buoys" in the Solent. All three types of Trident, bilge keel, fin-keel and retractable centre-boarder, were represented. At the end of the race it was not possible to distinguish any advantage or disadvantage to any kind of keel form.
The performance of the boats in the varying conditions during the race appear to be roughly equal. Although there were various changes of position, there was very little difference in time between the first and last boat home (eleven boats took part) considering the length of the course.
We started on a run in light airs, where a centre-boarder with his board up and his outboard motor removed, definitely had an advantage (all the other boats had inboard motors). The most interesting section was a close fetch, hard on the wind in an approximate force 3, when one would have expected the bilge-keel boats to be at a disadvantage, but this was not the case. I wonder if other PBO readers have any experience of other classes which have varying keel forms, where they can show a difference in performance.
It is often said that a bilge-keel is at a disadvantage as against a similar fin-keel boat, and although I must agree that one race might not tell the whole story, I would be interested in the experience of any other classes.
R W TYLER, Trident Owners' Association, 13 Trafalgar Road, Twickenham, Middlesex.
mikefield@woodenboatfittings.com
brianhumber
New member
Re: Lifting Keels
If the design is right and materials correct, the pins are just as reliable as keel bolts. Inspected the pin on my Sadler 45 last winter and found minimal wear on it after 13 years of bouncing around in the keel box.
If the design is right and materials correct, the pins are just as reliable as keel bolts. Inspected the pin on my Sadler 45 last winter and found minimal wear on it after 13 years of bouncing around in the keel box.
brianhumber
New member
Re: Lifting Keels
2nd that Vyv. looked at my pins last winter on the lifting ram and found minimal wear. Mind you if the helm hasn't got her 'in the groove' in a swell and she slams, the keel box gives out some horrible creaks and groans as the keel shoulders 'work' against the keel box bottom. Don't know if you know the design well, but I would'nt part with mine even someone offered another new boat in part exchange
2nd that Vyv. looked at my pins last winter on the lifting ram and found minimal wear. Mind you if the helm hasn't got her 'in the groove' in a swell and she slams, the keel box gives out some horrible creaks and groans as the keel shoulders 'work' against the keel box bottom. Don't know if you know the design well, but I would'nt part with mine even someone offered another new boat in part exchange
Twister_Ken
Well-known member
On long keels
Lots of stuff below about lifting keels - so here's a bit about long keels (LK).
PRO
Generally LK boats have very different lines underwater, with a rounded entry and deep bilges. This makes them far less 'crashy' going up wind in a seaway, and means they can absorb a good few gallons of spray and rain before bilge water starts swilling around and becoming a nuisance.
A LK boat is quite happy to dry out alongside, and minor irregularities on the bottom are less likely to tip her aft or forwards than is the case with a fin keeler.
They protect their sterngear and rudders well from pot bobbers and floating detritius.
Ballast is often 'encapsulated' so no worries about dodgy keelbolts.
They track well, and can often be made to sail hands-off. While this may not matter when being manually helmed, it does a lot to reduce power consumption under autohelm.
CONS
Depending on the form there can be more underwater surface area, making them stickier in light airs.
They generally don't turn as sharply as other keel configs. This doesn't matter when sailing, but can be a nuisance in tight quarters like narrow marina aisles. In light airs it might mean you need to back the headsail to help her turn.
Handling astern under power is usually idiosyncratic. I've had my LK boat now for a season and a half, and still I can't predict just what will happen when I go astern. Sometimes she kicks to port, sometimes to starboard and sometimes not at all.
They're not the best for settling into soft mud - fin keeler will tend to 'dagger' itself into the mud more or less upright, whereas the greater bottom area of a LK boat means it doesn't sink in so far, and may end up resting on the turn of the bilge.
You'll probably need to spend a few quid extra on antifouling.
All I can think of, hope it helps.
Lots of stuff below about lifting keels - so here's a bit about long keels (LK).
PRO
Generally LK boats have very different lines underwater, with a rounded entry and deep bilges. This makes them far less 'crashy' going up wind in a seaway, and means they can absorb a good few gallons of spray and rain before bilge water starts swilling around and becoming a nuisance.
A LK boat is quite happy to dry out alongside, and minor irregularities on the bottom are less likely to tip her aft or forwards than is the case with a fin keeler.
They protect their sterngear and rudders well from pot bobbers and floating detritius.
Ballast is often 'encapsulated' so no worries about dodgy keelbolts.
They track well, and can often be made to sail hands-off. While this may not matter when being manually helmed, it does a lot to reduce power consumption under autohelm.
CONS
Depending on the form there can be more underwater surface area, making them stickier in light airs.
They generally don't turn as sharply as other keel configs. This doesn't matter when sailing, but can be a nuisance in tight quarters like narrow marina aisles. In light airs it might mean you need to back the headsail to help her turn.
Handling astern under power is usually idiosyncratic. I've had my LK boat now for a season and a half, and still I can't predict just what will happen when I go astern. Sometimes she kicks to port, sometimes to starboard and sometimes not at all.
They're not the best for settling into soft mud - fin keeler will tend to 'dagger' itself into the mud more or less upright, whereas the greater bottom area of a LK boat means it doesn't sink in so far, and may end up resting on the turn of the bilge.
You'll probably need to spend a few quid extra on antifouling.
All I can think of, hope it helps.
chippie
New member
re Dugong
Thanks Dugong for sparking a stimulating discussion.
You could always sidestep the whole issue and consider a multihull.
Cheers, Chippie
Thanks Dugong for sparking a stimulating discussion.
You could always sidestep the whole issue and consider a multihull.
Cheers, Chippie
G
Guest
Guest
Re: re Dugong
Is that a multi-deepkeeler, a multi-finkeeler, or a multi-bilgekeeler, Chipps?
mikefield@woodenboatfittings.com
Is that a multi-deepkeeler, a multi-finkeeler, or a multi-bilgekeeler, Chipps?
mikefield@woodenboatfittings.com
