Why have keel preferences changed for cruising boats?

[Chotu]

Originally Posted by u4ea32

But clearly, a fat stern against a narrow bow means the stern provides a big impulse. The ocean surface ensures the impulse is periodic, resulting in larger and larger amplitudes.

Its quite remarkable. And very uncomfortable.

You have this part completely wrong. The less alike the shape of the the two extremities are, the more damping.

Pitching is caused by a harmonic oscillation at a fundamental frequency that builds the amplitude of the pitching with each successive and equal amplitude push from the bow and stern. The bow and stern need to have equal and opposing pushes to set up the oscillation. Picturing two equal weigh kids on a see saw. They get going very nicely.

If the pushes on the bow and stern are quite different in amplitude, you cause damping because the input frequencies are out of phase with the fundamental frequency of the system (boat). Now picture a huge fat kid on one side of the seesaw and a tiny baby on the other side. What happens? Nothing! Because the inputs are at different amplitudes and the see saw motion is damped.

Same with a boat hobby horsing.

Much of your post was discussing why irregularities and asymmetric features in the shape of a rolling boat cause damping. Yet when you change the axis of rotation to be athwartships instead of fore and aft, somehow everything you said about damping goes out the window? Now irregularities increase the pitching?

It’s illogical and contrary to the physics, which you had right in the rolling part of your post, then disregarded in the pitching part.

Everything else in your post regarding weight aloft, etc, is irrelevant to the subject. The subject is the “new hull shapes” and “fin keels.” Of course everything you said about weight aloft and in the ends is correct, but it doesn’t have much to do with comparing a 2 boats with different waterline profiles. You’re introducing extra variables that cloud the logic. You needed to just stick to the waterline differences to make an informed comparison.

[Paul L]

Originally Posted by Don C L

I know of the CCA rule issues, but I would wonder how the Alberg was loaded. If heavy chain and anchors are on the bow, and the stern has weight loaded there, and an arch, and solar panels and radar... perhaps it was loaded to encourage hobby horsing. It is probably fair to say boats like the Alberg were a 28 or 30 foot boat in a 35 foot body. If the weight is kept low and centralized it could be a very different ride. Still, boats like the Alberg 35 didn't get a good reputation for nothing.

A 35lb danforth with 35ft chain and 200ft rope rode on the bow. No arch, no solar, no mizzen mast and there's no locker in the stern large enough to put much in it to make a difference. It's the long overhangs and the low intial stability that really effect the ride in trying conditions. The good news is I was much younger when I owned the boat and thought all this was a right of passage to being a real sailor,

[Greg K]

Originally Posted by Don C L

I know of the CCA rule issues, but I would wonder how the Alberg was loaded. If heavy chain and anchors are on the bow, and the stern has weight loaded there, and an arch, and solar panels and radar... perhaps it was loaded to encourage hobby horsing. It is probably fair to say boats like the Alberg were a 28 or 30 foot boat in a 35 foot body. If the weight is kept low and centralized it could be a very different ride. Still, boats like the Alberg 35 didn't get a good reputation for nothing.

Agree. Take away the excessive overhangs and you will get a Shannon 28...similar beam and slightly less LWL. The A35 has a 31% overhangs, the Shannon has about half that (17%). Have not sailed on an A35, but the Shannon 28, in comparison to our former Cape dory 36 ( 25% overhang), doesn't hobbyhorses much at all even when punching into it under power.

Not all full or long keel boats hobbyhorse, just as not all fin keel boats slam and pound. As has been noted, there is much more at play in terms of hull design.

[MicHughV]

Hobby horsing has much to do with the buoyancy of a boat at each end. Length of overhangs is one thing, but so too, is the width of the boat at the bow and stern.

Interestingly, my first boat had a steel hull with hard chines. That boat would lay over, a chine would dig in, and stay put. Once it laid over, the waterline length increased, therefore the long overhangs kinda disappeared.

My next, and likely, my last boat, will have a full keel. I have numerous reasons for this decision, but they are my reasons. Chief amongst this is, I chose comfort over marginal speed difference.

[Don C L]

Originally Posted by Jim Cate

Considering the realities of cruising, keeping the ends of a boat shaped like the Alberg light is pretty hard to do. Like, where else but a forward chain locker will the weight of chain and anchor be put? And with the narrow hull, keeping stuff out of the lazarette is fantasy (IMO).

Day sailors and weekend racers have lots of latitude in such decisions, but cruisers not so much, and perhaps these realities have lead to the hobby-horse reputation amongst our crowd.

Jim

It's a fair criticism of the design and, I think, and how racing rules skewed the designs available for folks who aren't racing. I mean we don't HAVE to buy a boat that was designed with racing in mind, but there are just more of them! I always wondered why the overhangs had to be so HIGH and narrow though in the stern. To my eye it made more sense to get that extra waterline available sooner when heeling. Anyway when it comes to that kind of design maybe it's better just to plan on living (smaller) within the waterline. I mean, I can't do that, but all those other people should.
When I am ready to move up to a 29 foot boat, from my 28.5', I'll be heading over to the other side of the marina to see if those folks are ready to sell that beautiful Pearson Rhodes 41! I like rock and roll!

[Pete7]

Originally Posted by clakiep

less deep but wider. They morph than to the racer-cruiser boats and modern cruisers. They are alltogether less seaworthy in rough conditions, demanding more from their crew, which could well be observed at the one catastrophic Fastnet-Race.

Capt. Claus - ocean tramp of the eighties

And yet whilst everyone fawned over the Contessa 32s in the race, the forgotten Sigma 33s, one design yachts, completed or retired with aplomb. They of course have a deep keel and spade rudder.

[wingssail]

Greg, Your comment has an authoritative sound but it is all opinion and in my mind and not authoritative at all.

Originally Posted by Greg K

Marketing and margins are what drive the design and manufacturing processes of consumer goods today. The development of new materials and engineering solutions is at the core of that drive by making planned obsolescence possible.

Sorry Greg. The ability to make a boat which looks good, appeals to the buyers and sails well, is what drives design and manufacturing, not specifically marketing and margins. you are wrong in that.

Sailing boats are not any different than many other consumer products which are subject to manufactured consumer tastes. Today’s sailors want boats that can be easily maneuvered in marinas and have large attractive interiors. So you discount entirely that today's sailors also want boats which sail well or look nice? That is quite a cynical view. And I never met a buyer who gave a thought to how well a boat would maneuver in the marina, unless it was one who's current boat could not.
These two features require wide, flat bottom hulls with fin keels.
Compared to the classic plastic of the 60s, 70s and 80s, these modern hulls are cheaply assembled and lightly built with materials and fittings designed with relatively shorter life spans. Totally unsubstantiated opinion and wrong at that.
While capable of offshore duty, they are not primarily designed for offshore service nor have the durability that is necessary for a lifetime of open ocean sailing Hogwash, Greg
The time tested design and construction principles of moderate, balanced, seakindly hulls with full or long encapsulated keels and protected rudders will never be out of fashion with serious offshore sailors. Under sail, sailboats with such hulls offer an incomparably comfortable ride and ease of helming, unmatched by modern boats. Total unsubstantiated opinion They also offer much more security not only because of their strength but, also, in being better able to take care of themselves in adverse conditions, whether hove to or running with it under windvane selfsteering. They are not stronger, they cannot take care of themselves, they don't heave to any better, and they do not steer better, upwind or down, under windvane. PLUS, they cannot beat off of a lee shore, or make progress to windward in any condition. You are just plane wrong in every one of your assertions,

Greg, I have no idea where you got all of these "Facts" but I would be skeptical if they are backed up with offshore experience in the kinds of boats you are so quick to criticize.

My experience, in multiple kinds of boats, is quite difference.

[TeddyDiver]

Originally Posted by wingssail

Greg, Your comment has an authoritative sound but it is all opinion and in my mind and not authoritative at all.




Greg, I have no idea where you got all of these "Facts" but I would be skeptical if they are backed up with offshore experience in the kinds of boats you are so quick to criticize.

My experience, in multiple kinds of boats, is quite difference.

Back at you! You didn't have any proof to backup your opinions so it's biased one. Let me ask you one thing. You are to buy a new boat for four people and have two choices, one costing 150k and other 300k. The interior arrangements are about equal so are all other thing but the hull form and keel type. Which one you buy?

[TeddyDiver]

These two boats have about the same amount of interior space, the arrangements are different as there's some 80 yrs between them but if the latter were a new build that could be fixed. The price of sailboats are pretty consistent by $/weight so make your math..

Boat 1
Hull Type:~ Wing keel and spade rudder
Hull Material:~ GRP (Fiberglass)
Length Overall:~ 43'5" / 13.2m
Waterline Length:~ 36'4" / 11.1m
Beam:~ 12'10" / 3.9m
Draft:~ 5'11" / 1.8m
Rig Type:~ Cutter
Displacement:~ 19,845lb / 9,002kg
Displacement/Length Ratio:~ 185

Boat 2
Displacement: 14.75 tons
Ballast: 18,000 lbs. Lead
Length: 52.0 ft (15.8 m)
Waterline: 37 feet 3 inches (11.35 m)
Beam: 10 feet 3 inches (3.12 m)
Draught: 8.0 ft (2.4 m)
Rig Type: Yawl

[Rucksta]

Originally Posted by TeddyDiver

Back at you! You didn't have any proof to backup your opinions so it's biased one. Let me ask you one thing. You are to buy a new boat for four people and have two choices, one costing 150k and other 300k. The interior arrangements are about equal so are all other thing but the hull form and keel type. Which one you buy?

The one that sails best

[TeddyDiver]

Originally Posted by Rucksta

The one that sails best

Where? There's no such boat as "sails best" in all conditions.. and define best?
1st places in major races it would be the latter..

[Rucksta]

Originally Posted by TeddyDiver

Where? There's no such boat as "sails best" in all conditions.. and define best?
1st places in major races it would be the latter..

I bought one for $20K
For my needs and time of life it's best for me.

I like to sail.

If those needs change I'll buy a cat or a room in a nursing home.

[TeddyDiver]

Thumb! And why I build mine, kind of hybrid old and new.

[Greg K]

Originally Posted by wingssail

Greg, Your comment has an authoritative sound but it is all opinion and in my mind and not authoritative at all.

Greg, I have no idea where you got all of these "Facts" but I would be skeptical if they are backed up with offshore experience in the kinds of boats you are so quick to criticize.

My experience, in multiple kinds of boats, is quite difference.

Much enjoyed your spirited rebuttal, Fred. Considering that you sail a whiplash inducing rocket-ship IOR sled, it is not surprising that your strong opinion would be on the opposite end of the spectrum of mine. To be clear, my comment referred more to today’s mass manufactured, flat bottomed dock queens than late 70’s early 80’s custom or semi-custom built IOR ocean racers.
Still, you’re right, having sailed mostly traditional, full keel boats, my opinions are not supported by a lot of sea time on modern, mass production boats. Perhaps, after all, they don’t slam and pound in a seaway as badly as many have said, and perhaps they can be left on their own and keep their course while the helmsman jumps down below to make some tea. Perhaps their thinly skinned hulls and glued in structural keel support grids are actually stronger than a keel encapsulated in a couple of inches of solid fiberglass…etc, etc. Who knows, I might be wrong. It is just an opinion, and even though you may misconstrue it as authoritative, I assure you it is nothing more than gasbaggery on my part.
Your last comment regarding the inability of traditional boats to “ beat off of a lee shore, or make progress to windward in any condition ” is perhaps a bit of gasbaggery as well. Touche and peace

[wingssail]

Originally Posted by TeddyDiver

Back at you! You didn't have any proof to backup your opinions so it's biased one. Let me ask you one thing. You are to buy a new boat for four people and have two choices, one costing 150k and other 300k. The interior arrangements are about equal so are all other thing but the hull form and keel type. Which one you buy?

TeddyDiver, I didn't offer any proof, yes that is true, and to be honest, many of the attributes we're talking about are so subjective that it is hard to prove one way or the other (What is comfortable?).

However, I do have many years of ocean (and coastal) sailing experience, in a wide variety of boats, certainly including both heavy full keel "cruising" boats and high-end carbon fiber racers. but mostly in what I consider moderate modern boats. I just cannot justify the claims made about modern boats with my experiences. I don't know how come the boats I have sailed don't seem to pound yet they are said to pound. I don't know how come the boats I have sailed go in straight line, even in big seas, and can sail without someone on the helm every second yet that is the claim. I don't know how come the boats I have sailed on and seen after grounding and collisions didn't get destroyed any more than the heavy cruisers I've seen.

It goes on and on. People say that older, heavier, slower, boats are more comfortable, more directionally stable, stronger, and safer, without any objective proof, and I just haven't seen it.

It makes me skeptical. More than skeptical, I just reject it and wonder if it based on lack of experience.

The interior arrangements are about equal so are all other thing but the hull form and keel type. Which one you buy?

In the first place I would buy no boat which does not have superlative sailing performance. That is number one for me. This is because I love sailing. I love the sailing part. I know what a really nice sailing boat feels like and I would never be happy with a boat that couldn't produce that feeling. So hull and keel are important to me. Next it must be a strong and safe boat because going out in the ocean you are playing for keeps. You said the interiors were similar so that leaves the price. I could not afford a $300,000 boat so I'd look for a boat which meets my needs (above) for a much lower price. Fortunately there are many many boats that do for very low prices. The potential cruiser people shun the performance boats so the ones I like are available very cheaply.