Full keel, fin keel, or no keel (lifting keel/centerboard) for heavy weather and brea

[fourlyons]

Originally Posted by Don C L

huh? I haven't heard that. Is that to suggest that drifting sideways somehow protects the boat from the force of a breaking wave? I suspect whoever said that has probably not really tested that theory riding out a storm in a boat with a swing keel... broadside to breaking waves.

Actually this is a well established design theory to deal with breaking waves on the beam, used in the design for US Coast Guard surf boats amongst others. Steve Dashew discusses it in his book, Offshore Cruising Encyclopedia. The point is not to lie ahull waiting, but if struck broadside, with no deep keel and topsides designed right, the boat will skid sideways rather than trip and roll.

[Dieseldave]

So many great books articles and opinions on this from last week's latest "Only good Boat" magazine, to the Fastnet inquiry and beyond. I was indoctrinated into the full keel Alberg school of thinking on Long Island sound for goodness sakes. Some time sailing on more modern shaped boats has reversed my course lol. Great replies here. We always remember stormy weather lol even after many many years

[goboatingnow]

Originally Posted by Dieseldave

So many great books articles and opinions on this from last week's latest "Only good Boat" magazine, to the Fastnet inquiry and beyond. I was indoctrinated into the full keel Alberg school of thinking on Long Island sound for goodness sakes. Some time sailing on more modern shaped boats has reversed my course lol. Great replies here. We always remember stormy weather lol even after many many years

Keels had no impact on the fastnet issue

[wingssail]

Originally Posted by Don C L

huh? I haven't heard that. Is that to suggest that drifting sideways somehow protects the boat from the force of a breaking wave? I suspect whoever said that has probably not really tested that theory riding out a storm in a boat with a swing keel... broadside to breaking waves.

Hmm,Catamaran folks seem quite enamoured by that theory.

[Don C L]

Originally Posted by fourlyons

Actually this is a well established design theory to deal with breaking waves on the beam, used in the design for US Coast Guard surf boats amongst others. Steve Dashew discusses it in his book, Offshore Cruising Encyclopedia. The point is not to lie ahull waiting, but if struck broadside, with no deep keel and topsides designed right, the boat will skid sideways rather than trip and roll.

Hmmm... ok, but this whole idea of "tripping" on the keel has always perplexed me... I mean when you are coming down the face of a wave and you start to broach, yes in a way you could describe it as tripping, but it just seems to me that the keel, any keel, along with the mainsail and the heel angle, conspire to drive the boat around broadside to to the wave. So I just call that broaching. Maybe I am not thinking of the right situation for "tripping." Now, in my own experience having the main furled in those conditions helps a lot, and a spade rudder and a flat hull help too to keep her going the right way. But to have such a high center of gravity (as in, to raise a swing keel) in those conditions would cause me some... concernMaybe I'm old-fashioned, but I like a low center of gravity.

[cal40john]

Originally Posted by Don C L

Hmmm... ok, but this whole idea of "tripping" on the keel has always perplexed me... I mean when you are coming down the face of a wave and you start to broach, yes in a way you could describe it as tripping, but it just seems to me that the keel, any keel, along with the mainsail and the heel angle, conspire to drive the boat around broadside to to the wave. So I just call that broaching. Maybe I am not thinking of the right situation for "tripping." Now, in my own experience having the main furled in those conditions helps a lot, and a spade rudder and a flat hull help too to keep her going the right way. But to have such a high center of gravity (as in, to raise a swing keel) in those conditions would cause me some... concernMaybe I'm old-fashioned, but I like a low center of gravity.

In the post you quoted, the boat is already sitting broadside. It's been a long time since I read it, I hope I got the right skipper and boat, Phil Weld on Moxie would raise the boards, lie broadside, and slide sideways down the waves.

[Boatyarddog]

Originally Posted by Don C L

Hmmm... ok, but this whole idea of "tripping" on the keel has always perplexed me... I mean when you are coming down the face of a wave and you start to broach, yes in a way you could describe it as tripping, but it just seems to me that the keel, any keel, along with the mainsail and the heel angle, conspire to drive the boat around broadside to to the wave. So I just call that broaching. Maybe I am not thinking of the right situation for "tripping." Now, in my own experience having the main furled in those conditions helps a lot, and a spade rudder and a flat hull help too to keep her going the right way. But to have such a high center of gravity (as in, to raise a swing keel) in those conditions would cause me some... concernMaybe I'm old-fashioned, but I like a low center of gravity.

You are going to be "trippin" if you surf down waves, the flatter the hull the worse.
V hull design and, DRAG SOMETHING, to slow you down, I'm sure you want that wave to roll under you.
You lose steering when surfing waves because your traveling the same speed as the wave.
Rudders only work when water runs by them, either way, transom to Bow, or Bow to Transom

[Don C L]

Originally Posted by cal40john

In the post you quoted, the boat is already sitting broadside. It's been a long time since I read it, I hope I got the right skipper and boat, Phil Weld on Moxie would raise the boards, lie broadside, and slide sideways down the waves.

Oh, the trimaran? I've always admired that boat! Newick's boats are my dream boats. I didn't post a quote about that, but a trimaran, broadside to waves; that's a bit different than a monohull with a swing keel, no? I have yet to sail one so I hope some folks with trimarans will chime in!
Is it really sliding sideways down the face of a wave? I'd like to see that.

[Don C L]

Originally Posted by Boatyarddog

You lose steering when surfing waves because your traveling the same speed as the wave.
Rudders only work when water runs by them, either way, transom to Bow, or Bow to Transom

Actually I have not experienced loss of steering while surfing, it's in the broach that steering goes south! Only the breaking part of the wave is falling water, the rest of the water in the wave is pretty much staying where it is except for moving up and down as the wave passes. The wave has the speed moving through the water in other words.

[Boatyarddog]

Originally Posted by goboatingnow

The vast vast vast vast vast majority of fin keeps don’t fall off either

Let’s stop peddling this nonsense that keels fall off. There have been a few well documented failures often where the keels are extreme or were tampered with.

suggesting a long keel doesn’t fall off as an advantage is like quoting an advantage that the Hull floats.

In my opinion most boats can be sailed reasonably comfortably in most seas. I once delivered a long keel across the Atlantic. She rolled like a dog. Often modern boats are so good at sailing they get pushed too hard and this can cause


The spade rudder is unquestionably one of the best hydro dynamically. This is want you want 99.99 % of the time.

Sheesh.

Except spade rudders have little protection, skegs protect the rudder better, so I Disagree on the 99.9% this is what you want...claim.
To each their own.
KEELS FALL OFF, Interesting Sailboats: KEELS FALLING OFF
And, ENCAPSULATED keels don't fall off.
Haven't heard one story of that ever happening, have you?

[Don C L]

Originally Posted by Boatyarddog

And, ENCAPSULATED keels don't fall off.
Haven't heard one story of that ever happening, have you?

Actually I hadn't either until this topic came up in another thread. It wasn't that the keel can fall off, but that in a hard grounding the keel may break open enough to allow the ballast to fall out. I'll see if I can find that thread.

[Boatyarddog]

Originally Posted by Don C L

Actually I hadn't either until this topic came up in another thread. It wasn't that the keel can fall off, but that in a hard grounding the keel may break open enough to allow the ballast to fall out. I'll see if I can find that thread.

Can't say that that wouldn't happen in that instance, but that's going to be a lot less often. Extreme!
I'd also bet the fin keel may as well "Pop".

When you "Yaw" that's basically a minor version of losing steering, but you can recover in that instance.

With a broach you cannot out steer the boats direction, because the speed won't allow water to run over the rudder and you may well drive the bow into the wave trough.
This happens quite a bit of the time.
"Death roll" is the action when the wave rolls the boat over in a wave.
SV Cloud Duster

[Jim Cate]

Originally Posted by Boatyarddog

Except spade rudders have little protection, skegs protect the rudder better, so I Disagree on the 99.9% this is what you want...claim.
To each their own.
KEELS FALL OFF, Interesting Sailboats: KEELS FALLING OFF
And, ENCAPSULATED keels don't fall off.
Haven't heard one story of that ever happening, have you?

Actually, if you read through the interesting discussions appended to the linked article there are several mentions of encapsulated keels falling off or losing their ballast. And I have personally seen FRP encapsulated iron ballast rusting and swelling to the point that the skin of the keel had burst. Not a catastrophic failure, but perhaps catastrophic to the owner's bank account.

And on a different bent, if routine inspection and renewal are to become mandated, I do hope that the practice of casting the keel attaching studs into the lead is discontinued. This convenient methodology makes replacement of the studs very very expensive.

Jim

[rslifkin]

Originally Posted by Boatyarddog

Except spade rudders have little protection, skegs protect the rudder better, so I Disagree on the 99.9% this is what you want...claim.
To each their own.
KEELS FALL OFF, Interesting Sailboats: KEELS FALLING OFF
And, ENCAPSULATED keels don't fall off.
Haven't heard one story of that ever happening, have you?

Yes, a skeg should handle an impact better. But that doesn't mean you can't build a damn strong spade rudder. I'd rather have the spade rudder and just make sure the mountings are strong enough that it's not a weak point.

[Boatyarddog]

Originally Posted by Jim Cate

Actually, if you read through the interesting discussions appended to the linked article there are several mentions of encapsulated keels falling off or losing their ballast. And I have personally seen FRP encapsulated iron ballast rusting and swelling to the point that the skin of the keel had burst. Not a catastrophic failure, but perhaps catastrophic to the owner's bank account.

And on a different bent, if routine inspection and renewal are to become mandated, I do hope that the practice of casting the keel attaching studs into the lead is discontinued. This convenient methodology makes replacement of the studs very very expensive.

Jim

Didn't see those claims.. Could you point them out?

Some builders build thin integrated keels that can be weak designs.
while technically "Encapsulated" they subject to higher incidences of failure.
True with most things, good design, not so good.
SV Cloud Duster