Full Keel vs Fin Keel

[fireman182]

Originally Posted by SalingSue

Fin, but by fin I don’t mean a thin deep razor blade attached to a bulb, go look at say a Amel

Though nothing wrong with a full keel, but left to my own devices I’d go fin with a skeg mounted rudder and a design that also protects the prop.

What is the advantage to a fin keel that you feel would make it better than a full?

[fireman182]

Originally Posted by Mike OReilly

The keel is one factor in the multi-factor puzzle of choosing a boat. It certainly wasn't the most important consideration for me, but it was on the list.

My boat has a real full keel. Not some semi or partial or cutaway thing; a FULL keel. It's encapsulated, so very strong and safe. It protects the rudder and prop well. It keeps the boat going straight, and resists lateral rolling.

Downsides are that it's a major PITA when it comes to tight maneuvering and docking. It adds to the wetted area, meaning it takes more effort to get her going. Plus, it means a much bigger area to cover with expensive bottom paint.

All in all I would rather have a modified fin with a skeg hung rudder. This, to me, seems like the sweet spot for keels. Good tracking, solid protected design, but still able to maneuver reasonably well.

But as the song goes, You don't always get what you want.

Yes they are bad around the docks. I agree.

Would you say that having tight maneuvering with a fin is the priority over all the pros of full keel you listed?

I wish I had a fin keel when docking and glad I have a full keel when running aground.

Do you find your full keel tends to handle under water currents poorly?

[peter loveridge]

there are two aspects where a full keel wins hands down, that are usually never mentioned. If you sail in a place like Maine, where there are no end of pot lines and buoys in the water, a full keel is much more forgiving, especially under sail. If you sail in a place where you only have primitive slipways, or you have to dry out against a wall, the full keel wins again, especially if you're talking about a short fin and a spade rudder

[fireman182]

Originally Posted by brewski

I mean this is a never ending argument, but there's no evidence that a fin keel (especially a deep bulb keel) is "more seaworthy" than a full keel.

Faster? Yes.

More maneuverable? Yes.

But seaworthiness entails much more than just what boat goes the fastest and how well you can pick your way around a tight anchorage.

Needless to say there are also fin keel boats that are truly dogs, and full keel boats with surprising performance.

Its literally all compromises, and some will be happy with a full keel while others will only be satisfied with a deep bulb. Some will choose Alubat type swing keels, and others will choose the stable beam of a catamaran.

But let's not go around pretending one design is the end all, be all in seaworthiness.

Good points.

Could you fathom a guess as to why speed is a HUGE factor to alot of people when it comes to buying a sailboat?

Understandably racing would be the obvious factor but in terms of speed these things are slow. I would look to a powerboat for real speed.

When comparing full to fin the speed factor isn't that great. 6 knot difference max?

At the end of a sail, does it make that much of a difference?

[Dockhead]

Originally Posted by rbk

. . . it’s not just about the type of keel, as hull shape, rig and sails also play major rolls as well. Look at the whole boat not just the type of keel.

Well, except all these things are not separate qualities, but intimiately related to each other. Full keel = tubby hull form and lower rig with lower aspect ratio. Such a boat doesn't go well upwind so very often you see large engines and tankage. And often a ketch rig. This is actually a good combination of qualities; not very efficient but very comfortable and easy to handle.

[boatman61]

Originally Posted by fireman182

Our boats are lifted 50 feet into the air by a giant crane twice a year.

The club members who work the slings under the boat have to know where the keel is and what type it is. Especially on a full keel because of the potential to slip as keel moves forward.

We're talking 30 feet + boats

Oddly enough, I often get asked if I'm going to cross the Atlantic BECAUSE I have a Westsail with a full keel

Ahhh.!!! That's a different thing, case specific purely for lift out purposes..
Understandable as no one can be expected to know every boats keel layout.
However "At the dock" is vastly different from 'for craning/liftout purposes'..

[sailorboy1]

Originally Posted by fireman182

Hey Guys,

I'm just looking for thoughts on the great modern sailing debate. Old vs New. Traditional vs modern.

Full Keel vs Fin Keel. What are the pros and cons for each?

Is the fin keel the most popular design of todays modern sailboat? Is it safe?
Strong enough for the worst ocean weather?

What are your thoughts?

I came up with a few pros and cons.

Full Keel

Pro

Wont break off
Tracks better
Protects prop
Protects Rudder

Con

Difficult to maneuver
Heavier design


Was keel design a big decision when buying your boat??

Oh come on do we really another of these topic threads? Cant you read all the old ones?

Yes I can and will not pay any more attention to it

[Cheechako]

The answer is maybe.
I've never heard of a long keel failing. (be careful, people here will insist a "full keel" must be full length! But most of us know what you are asking) They are almost always molded as part of the hull. It's one less thing to evaluate or worry about IMHO.

Bolted on keels fail from time to time. Most are fine, until they are old ...then the problem is "you dont know". Occasionally a new one falls off! But it's rare. Damage to un attached rudders is not uncommon at all.

A fin keel boat almost always is "busy" and requires more care at the helm. But sails a bit better to weather.

I have personal experience with fin keel boat hitting a rock at 5 knots suffering significant damage. A couple months of work and $30k cost to repair.

I have personal experience hitting a rock or hard bottom 3 times with a molded long keel with no damage other than a scrape on the keel. Once at 5+ knots.

Maneuvering: Actually, I prefer a long keel boat to a fin. I'm used to it, I know how to use it. Really have not had an issue. Prop walk is another tool.

[TrentePieds]

Quote: "Understandable as no one can be expected to know every boats keel layout"

Uhm... a quibble:-): Every boat owner knows, or should know, just exactly where the slings are to go. Communication of that knowledge to the navvies at a yard, or to, say, a delivery skipper, can be done either by marking the hull (aircraft style) "sling here", or by furnishing a profile drawing of the hull with the sling positions indicated.

TP

[Mike OReilly]

Originally Posted by fireman182

Yes they are bad around the docks. I agree.

Would you say that having tight maneuvering with a fin is the priority over all the pros of full keel you listed?

I wish I had a fin keel when docking and glad I have a full keel when running aground.

Do you find your full keel tends to handle under water currents poorly?

No, like you, I wouldn't prioritize tight maneuvering over good tracking and strength/security. But I might if I spent a lot of time in marinas .

Yes, currents are another challenge. I won't say negative, but us full keelers definitely have to be aware of strong currents, especially cross-current or eddy situations. When I sailed down the St. Lawrence there were places where you could really feel the river currents, and had to be careful not to get abeam of them.

[fireman182]

Originally Posted by boatman61

Ahhh.!!! That's a different thing, case specific purely for lift out purposes..
Understandable as no one can be expected to know every boats keel layout.
However "At the dock" is vastly different from 'for craning/liftout purposes'..

Owners are expected to know their keel and sling points. The topic always comes up and pros and cons.

Like clock work. I like it, not every sailor is on forums beating a dead horse

[fireman182]

Originally Posted by Dockhead

Well, except all these things are not separate qualities, but intimiately related to each other. Full keel = tubby hull form and lower rig with lower aspect ratio. Such a boat doesn't go well upwind so very often you see large engines and tankage. And often a ketch rig. This is actually a good combination of qualities; not very efficient but very comfortable and easy to handle.

Are you saying the keel determines the tank and engine size?

Almost all full keels are cruisers with more cargo capacity than racers so it would be more than likely that the fuel tank and engine match its design purpose

[fireman182]

Originally Posted by sailorboy1

Oh come on do we really another of these topic threads? Cant you read all the old ones?

Yes I can and will not pay any more attention to it

No worries friend. I don't imagine full keels interest a Hunter sailor much.

You've got bigger fish to fry 🤣🤣🤣

[fireman182]

Originally Posted by Cheechako

The answer is maybe.
I've never heard of a long keel failing. (be careful, people here will insist a "full keel" must be full length! But most of us know what you are asking) They are almost always molded as part of the hull. It's one less thing to evaluate or worry about IMHO.

Bolted on keels fail from time to time. Most are fine, until they are old ...then the problem is "you dont know". Occasionally a new one falls off! But it's rare. Damage to un attached rudders is not uncommon at all.

A fin keel boat almost always is "busy" and requires more care at the helm. But sails a bit better to weather.

I have personal experience with fin keel boat hitting a rock at 5 knots suffering significant damage. A couple months of work and $30k cost to repair.

I have personal experience hitting a rock or hard bottom 3 times with a molded long keel with no damage other than a scrape on the keel. Once at 5+ knots.

Maneuvering: Actually, I prefer a long keel boat to a fin. I'm used to it, I know how to use it. Really have not had an issue. Prop walk is another tool.

Great points! Additionally I would say full keels draw less water. I could be wrong but rarely are they more than 6 feet draft.

Less likely to hit that illusive rock

[holtjp]

Many great points have been made in this thread and numerous others, but it might be worth considering a couple of cautions. First, while the very general differences between the two hulls might be grounded in some degree of truth, that does not mean every boat with a full keel will be a slow, can't point into the wind slug, nor will every fin keel boat be a speedster. There are some well known full keel designs, the Bristol Channel Cutter comes to mind, that are much better performers than their hull form might indicate. This is especially true if you boat is loaded up for long-distance cruising. Many fin keel boats will lose a lot of their light wind speed advantages when carrying a full cruising load. This is also true when winds start to push past the 10-20 kt sweet zone. A well designed, full keel boat will be generally be capable of maintaining a higher level of speed while still keeping the crew acceptably comfortable. The sail plan carried also plays a significant and obvious role in both speed and upwind performance. A full keeled boat with a well designed rig can very often sail faster and point higher than many finned keel boats with average rigs.

Second, like every aspect of boating, the type of cruising you want to do and the cruising grounds you want to spend most of your time in should play a big role in any boat purchase decision. I sail a full keeled boat in the waters of Maine and the Canadian Maritimes. Given the almost impenetrable barriers of lobster pots here in Maine I would never own anything but a full keeled boat. I can sail through the pot buoy barrier, especially under sail, with little or no concerns of wrapping a buoy around a prop or rudder. To me, this was a huge factor in my boat purchasing decision.

Bottom line, you will be better served looking at the performance and general sea qualities of specific boats rather than summarily focusing on one class over the other because of the very generic attributes associated with their hull form.