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  #11  
Old 11-13-2007
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A couple quick points here.....The reality of all of this is that boats are a system. Properly designed as a system where the hull form, rig and appendages are all working together, a fin keel/spade boat will offer significant gains in speed and should offer no liability to motion comfort, seaworthiness or tracking, and may actually offer significant advantages in all cases.

Whether or not a boat has a fin keel has little bearing on whether the boat has a comfortable motion, slams in a seaway, how much it can carry or whether it can tollerate weight in the bow. That is more a product of hull form and keel/rudder shape decisions that full keel or fin keel.

But, and this is a big 'but', most fin keel boats were designed for coastal cruising or some racing and so prioritize performance and cost over seakeeping or motion confort. This means that it takes more time and knowlege to buy a fin keeled boat to go offshore. Since one of the few justifications for buying a full keel is going offshore, a larger percentage of full keeled boats are designed to be offshore cruisers. Often these boats are truely hampered as coastal cruisers so it really makes sense to ask yourself do you really need a full blown offshore cruiser.

When you ask about the speed difference, it is not just a simple matter of speed but also the percentage of time spend sailing. As an example, a few years ago I spoke to a fellow who single-handed a high performance 38 footer from South Africa to the Carribean. He averaged 150 miles a day and used less than 20 gallons over the whole trip (including going through the Duldrums). He left South Africa with a 55 footer which he described as a reasonably modern full keeled boat. As I recall he said that the 55 footer arrived something like 10 days later and used well over 100 gallons of fuel.

I do want to clarify one more point, Boats with a Brewer notch are an example of a long fin keel skeg hung rudder.

Jeff
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  #12  
Old 11-13-2007
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Couple of points Ajari.

Maybe of no great relevence but one of the fin keels advantages is agility under power, particularly in reverse. If you have a look at the thread "Pilot House ??? " from yesterday you'll see the narrow passage I had to reverse Raven up to get out of the slip. Its probably about 40 odd metres and not much more than a single boat width yet with a fin keeler I can reverse straight out. It's as easy as reversing a car. Do that in a full keeler and Oh Mama ! They do not like reversing at all.

Our girl is a fin with spade rudder. If I had my preference it would be fin with skeg hung rudder. To me that is a damn near perfect compromise.

Obviously this is not a set rule but you will find that despite the full keel being slower than a fin this is often not the case when reaching under normal working sails.

At this point you start moving into discussion of ketchs, schooners and the like where theoretically they are slower than a comparative sloop but when you free her up a bit and slap on a mizzen staysail the ketch picks up her skirts and flies. Same applies to gaffers. The speed than an old full keel gaffer can achieve when on a reach can be quite surprising.
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  #13  
Old 11-13-2007
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Simply from my observations, and not from any theoretical standpoint, if you'll be doing a lot of manuvering (in and out of slips, narrow channels, etc) a fin would be better. If you're passagemaking then the full would seem to work better. That though, is simply my opinion.

Currently at 34 12 22 N 77 48 01 W, Wrightsville Beach, NC
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Old 11-13-2007
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I would second Valiente's post. I cruised off shore on a fin keel boat, and spent many years racing them. One of the things I made sure I had on my next blue water boat, was a full keel. Do I want to sail it into my slip? No. Is it a joy to back up? No, unless you want to back to starboard. Would I buy a full keel boat as a boat for just day sailing in and out of a tight marina? No. However, in my experience, off shore
cruising is about moving in straight lines for a long time, and the less squirrelly your boat moves the better. What ever helps the self steering do the work for you makes the passage so much sweeter.
I love racing boats, I just don't want to go offshore in one without a really good crew, and even then the goal is to get off the water as fast as possible.
Full keel boats track wonderfully, and take much less effort, in my experience, from the helm. My whole philosophy, and I don't think there is only one right answer, is to be comfortable with as little stress to the boat and crew underway as possible. So for me, full keel, ketch rig, center cockpit, and pilothouse are all parts of the same puzzle. So spread the load and enjoy the trip.
And as Valiente also points out, tons of storage space.
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Old 11-13-2007
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Jeff H,
Just a minor point but Ted Brewer likes to call that style a Brewer bite not a notch.
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Robert Gainer
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The fin keel was an invention at a particular point in history. Like all new ideas the old timers considered it dangers and it didnít catch on when it was first introduced by Nat Herreshoff. When Bill Lapworth used it in modern times it was a resounding success especially when combined with the then relatively new material called fiberglass. But it still meets with resistance and ridicule from the old school.

Both types have good and bad aspects to the design but each can be a good seaworthy design if designed and built correctly. The key question is how the overall package is designed. As I have said before a boat is a system and it needs to be designed with that in mind. To decide which type is suitable for your style of sailing requires you to make decisions that canít be made using someone elseís preferences and prejudices. You need to sail on examples of each type and decide for yourself how you want to handle heavy weather, provisioning, boat handling and even maintenance. All of those things are very different for each type of boat. Itís always a good idea to discuss the differences and trade ideas but you need some experience of your own to be able to weigh the relative value of each point unless you are willing to blindly accept advice from people who may or may not know what they are talking about. But more then that because route planning, storm tactics and almost everything else is determined by boat type you need an overall understanding of the entire process to intelligently select a boat.
All the best,
Robert Gainer
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Old 11-13-2007
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Jeff H,
You say, ďBy the classic definition of a fin keel any keel whose bottom is less than 50% of the length of the boat is a fin keel.Ē You have used this statement frequently and its wording implies that it is a well know and published statement. But I canít find any reference that defines it this way. This is a convenient definition but it would be nice to have something to cite when saying this. Where did this come from?
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Robert Gainer
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  #18  
Old 11-13-2007
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Thanks Robert.

I agree, if I have learned one thing from my time on this forum is that no one can choose for me, and that just about every variation; be it rig, keel, hull style etc. is right for some circumstances, and disasterous for another.

When I ask opinions I am always happiest when responses include context; and that is what I have enjoyed most about everyone here. (with very few exceptions)

Until I have the opportunity to try these variations for myself; I will endeavor to learn whatever is possible from the personal experiences of others.

Thank you all for very eriudite replys.

Fred
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Old 11-13-2007
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Quote:
Originally Posted by Jeff_H View Post
I do want to clarify one more point, Boats with a Brewer notch are an example of a long fin keel skeg hung rudder.

Jeff
True, but I think performance-wise they are classed with the full-keelers. I also concur that the boat is a system, but we are speaking in generalities here, hence the lack of precision.

There is one other factor, of course: time. The full keeler doesn't HAVE to burn that fuel...it is perfectly capable of sailing, albeit generally more slowly, than the fin keeler. Of course, the full keeler tends to have more tankage, more water and more stores aboard.

If the fin keeler hits extended calms, it is possible to burn up all the fuel, drink the water and eat the food...and still be becalmed.

Similarly, it's said the fin keeler can "outrun" bad weather, while the full keeler can "endure" it.

Both statements are partly false: a fin keeler making 9-10 knots in front of a storm doing 25 knots isn't outrunning anything, and a full keeler that can't trail a drogue or heave-to properly is likely to come to grief.

So parts of the equation come down to skill, the real need to go at a particular speed, and the luck of the draw. A single sailor can take a twitchy Open 60 at 25 knots through the Southern Ocean, and some of the best dive sites are on ships deemed "unsinkable".

Let your skills and favoured style of sailing dictate your choices. Understand that there are very few boats below the millionaire class that feature fast, high-pointing fins, skegs and with capacious tankage, and there's a few full keelers that can move very smartly in most conditions.

I would say, however, that if you're in that much of a hurry to cross oceans, consider air travel. It's much, much cheaper and much, much faster, even than an Open 60...
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Old 11-13-2007
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Quote:
Originally Posted by PBzeer View Post
Simply from my observations, and not from any theoretical standpoint, if you'll be doing a lot of manuvering (in and out of slips, narrow channels, etc) a fin would be better. If you're passagemaking then the full would seem to work better. That though, is simply my opinion.

Currently at 34 12 22 N 77 48 01 W, Wrightsville Beach, NC
It's my opinion as well. Maneuvering in tight spaces under power is definitely clumsier with my pilothouse cutter, but I attribute this in part to my windage. Part of this is being addressed via the installation of a four-bladed feathering prop, which will be pitched in reverse to provide considerably more stopping power and less prop walk. The other way to address this is to go back to older methods of maneuvering in tight places via the use of spring lines and warping off the dock or wall. On moorings, you sometimes get better results sailing off than motoring, or by using a combination.

It's best practised on a sea wall with little else around at first, but warping can put the bow where you want it even in contrary winds, but like heaving-to and knowing when to reef, it takes real practice and every boat is different. In my case, I have to dock "blind" as I can't see the dock from the pilothouse, and I have to make sure I don't clip the davits of my neighbour (I have a slip at the end of a finger.) This is when a good set of fenders, some skill at aiming, and the faith in going into neutral and trusting inertia to keep you moving comes into play. My wife is no long-jumper, but she hasn't got herself or the mid-ship spring line wet yet.
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