Full Keel to Fin Keel.

[thomm225]

Originally Posted by jharding

The idea of a lighter faster boat with modern electronics being able to avoid storms is great. But it just doesn't work that way, you will still get caught in storms, I love my seakindly, long keel, heavy boat. It always does what it should and makes me feel comfortable and confident, I'll take that any day.

Good electronics for weather info might be a nice thing to have though on a relatively slow full keel boat under 30'.

It would be nice to be able to pick a good weather window before attempting a crossing and to be able to get reports while offshore. A Sat phone would be good also. These items can be purchased with the money saved by staying with an older full keel style boat rather than moving to a larger Fin (or larger whatever). Sailing at the right time of year is important also

Btw, I'm not really seeing your boat as being all that slow at 52' no matter what type keel is has......with a PHRF near 105

[nortonscove]

We had to go there with the keel falling off issue that is in reality a non-issue. Keep an eye on the condition of your boat and this will never happen. Old boats are designed differently for a reason. The same reasoning used to explain why your car doesn't come with a horse out front. The way we design has changed and I'd say having sailed both types, for the better.

As for the mass production boats we see today I love them and all their amenities. Without them I might not be out there because my wife would sooner just stay at work then be uncomfortable.

[wingssail]

Originally Posted by Rangemarker25

Now I doubt this is correct.

Many of us love sailing and we have full keels.

For one thing we feel we are working with our boat especially when sailing upwind especially in strong wind. We have to make the best plan to get where we are going by using current and best tack etc

On the smaller full keel boats, it's sort of enjoyable to see that yes the boat can be a bit tender at first and it will roll over to a certain point but then will dig in and stay there

Here's an old full keel boat someone has fallen in love with and this boat does have some age on it. Someone has definitely decided it's worth saving and I'm thinking loves sailing the thing

OK, you make some good points, I was generalizing, I was too harsh.

It's just that where I sail very few owners of full keel boats ever go sailing.
They do motor from place to place occasionally, but you rarely see them leave the dock just to go sailing. (there is one, a friend of mine with a Baba30, who goes sailing several times a year). But the bay always has a few boats out on it with sails up and heeled over, and they are virtually always modern, fin keel, fun to sail boats.

But I guess I can't say its all about love of sailing or the fun of the boat that makes the difference.

[thomm225]

Originally Posted by wingssail

OK, you make some good points, I was generalizing, I was too harsh.

It's just that where I sail very few owners of full keel boats ever go sailing.
They do motor from place to place occasionally, but you rarely see them leave the dock just to go sailing. (there is one, a friend of mine with a Baba30, who goes sailing several times a year). But the bay always has a few boats out on it with sails up and heeled over, and they are virtually always modern, fin keel, fun to sail boats.

But I guess I can't say its all about love of sailing or the fun of the boat that makes the difference.

Well I guess I don't see a lot of full keel boats out there sailing but there are a few.

Most times it's me and the sailing school Capri 22's that I see a lot and the school's late model Hunters. Very pretty boats they are as well

I see some nice fin keel boats also usually 42' plus with plumb bows.

Funny thing is sometimes they aren't sailed to get max performance. Last weekend I did an out and back of maybe 4 hours and as I gybed to go back in there was a new style fin keel boat/plumb bow of at least 45' maybe 500 yard to my stern after I completed my gybe so I figured I try to stay ahead of him for a long as I could.

We were sailing a close reach I'd say. After a time, I noticed I was maintaining position and maybe pulling ahead a little. Then I noticed he only had a large jib/genoa up. I was also outpointing him since I had both sails up

After I had really made good progress pointing in a bit he would steer way to windward and luff his jib to get closer in. We were headed toward the same creek 4 miles ahead

I just don't get it a guess. That boat could have rolled over mine at any time if the crew had raised the main. I continued to gain ground then lost track of him after entering the creek and going forward to lower and tie down the main while motoring in

Maybe I just raced too long and never learned to go for a relaxing sail with the wrong sail up

[Cpt Pat]

Originally Posted by wingssail

Not quite, Cpt Pat...

I agree that it's a myth that fin keeled boats can't heave to - and I don't want to perpetuate that myth. I do deliveries, so I've had experience with a wide variety of sailboats. I've yet to sail one, fin or full keeled, that can't be hove to. But the behavior of many fin keeled boats (I haven't sailed them all) while hove to is far less stable. The ones I've sailed exhibit a phugoid oscillation (see https://en.wikipedia.org/wiki/Phugoid for an aerodynamic example of phugoid oscillations in pitch) that causes them to continually yaw port and starboard (sometimes dramatically), and they can be upset by wave action enough for the phugoid to cause a jibe. I've never felt confident that I could leave such a boat to tend to itself.

I'm willing to trade off a little speed in light airs for the yaw stability of a full keel. Other's aren't. I won't judge the taste of others.

These fin versus full keel preferences are nearly a religious argument. It's so much a question of taste and personal preference that proponents of each could argue forever and never resolve their differences. Which is better: red or green? Your preference is your preference, and mine is mine. About all we may agree on is that fin and full-keeled boats behave differently.

My statements are based on my personal experience and taste. It's an opinion - which I believe the OP was soliciting. As indicated by posts above, there are others who share my preference for full keels. But I don't want to argue over how many angels can dance on the head of a pin. Everyone's taste is valid for them. To each his own!

[thomm225]

Well it's good that you have sailed both.

You can then make a good decision on which boat is best for you.

I love the way my old boat looks but I also like some of the fin keel boats. (actually I like most all sailboats)

I've only sailed this full keel boat and small racing boats. I've crewed on a fin keel (Soverel 30 1980) but that's about it.

[Cpt Pat]

(session timed out)


Some of the differences between fin and full keeled boats are important, but I'll defer to the well-respected authors of the books: "Desirable and Undesirable Characteristics of Offshore Yachts," and, "Seaworthiness : The Forgotten Factor," who present those differences very well.

[TeddyDiver]

Originally Posted by Cpt Pat

(session timed out)


Some of the differences between fin and full keeled boats are important, but I'll defer to the well-respected authors of the books: "Desirable and Undesirable Characteristics of Offshore Yachts," and, "Seaworthiness : The Forgotten Factor," who present those differences very well.

Vigor and Marchaj

[thomm225]

Originally Posted by Cpt Pat

(session timed out)


Some of the differences between fin and full keeled boats are important, but I'll defer to the well-respected authors of the books: "Desirable and Undesirable Characteristics of Offshore Yachts," and, "Seaworthiness : The Forgotten Factor," who present those differences very well.

I have the Marchaj book on Seaworthiness and if I remember correctly he spends quite a bit of time comparing fin keel (especially racing fin keel boats with a Capsize Screening Formula of above 2.0) and full keel bats.

He also uses the Contessa 32 in some examples with it's 157 degree AVS.

Many here on CF will call the books dated though since they are 30 years old plus.

[Cpt Pat]

Originally Posted by Rangemarker25

Many here on CF will call the books dated though since they are 30 years old plus.

Fortunately, physics doesn't have an expiration date. There was a lot of testing after the Fastnet '79 disaster. I'm not aware of any more recent extensive follow-on tests. If the research exists, I'd love to see a reference.

[Chris31415]

Originally Posted by barnakiel

Well, imagine you immerse this sphere half in water. Now:


0.9 is half sphere volume, all sphere is 1.8 cube meters volume.


and the half area of this sphere is 15,2 sq meters

....

Cheers,
b.

Better check your math b.

[barnakiel]

Originally Posted by Chris31415

Better check your math b.

EDITED:


I did now.


Sphere radius 0.755 displaces 1.8 cubic meter at half area (sic!!!) 3.5 sq m.


How embarrassing!


I mean: to me too BUT why then do 'they' claim they are minimizing the wetted area while the opposite seems to be true?


Could you possibly chime in and expand on what you know and think about this?


Very best regards, and thanks for putting me right!


barnakiel

[TeddyDiver]

Originally Posted by barnakiel

EDITED:


I did now.


Sphere radius 0.755 displaces 1.8 cubic meter at half area (sic!!!) 3.5 sq m.


How embarrassing!


I mean: to me too BUT why then do 'they' claim they are minimizing the wetted area while the opposite seems to be true?


Could you possibly chime in and expand on what you know and think about this?


Very best regards, and thanks for putting me right!


barnakiel

You don't mind if i chime in too? The keel is the only place where the wetted area is minimised. The flat bottom (and square transection) is to minimise weight ie displacement and maximise the hull internal volume. The minimised weight allows less weight and area with smaller keel and thus a cheaper boat per living spaces volume. The rest is marketing BS..

Teddy

[Chris31415]

I am by no means an expert, but this is what I think.

The full/fuller keel boats simply weigh more, so if you model both as spheres, the full keel sits lower in the water and has a greater wetted area.

Why? The full keel has a shorter lever arm then a fin keel, so it requires more ballast to generate the same righting moment.

I think the hull shape, flat bottom vs. the “U” shape, is a separate design consideration.

Chris

[RaymondR]

Both of my cruising boats have been full keel and there is a number of things I like about them.

There is a lot of space down there on top of the ballast to store heavy items like spare anchors and chain.

It's also a good place to have fuel, water and sullage tanks.

It's not anywhere near as nerve wracking when on the slip.

Having a rudder with gudgeons top and bottom on the back end of a full keel is very reassuring.

Running aground and bumping the bottom is much less stressful.

Since I live aboard and cruise as a lifestyle I prefer the long keel. But if my thing was just sailing I'd prefer a go faster with a fin keel and spade rudder. The wetted surface and lift counts.