Hull form, Keel and rudder design... merits and hazzards.

[Captain Smollett]

with light displacement.

Don't underestimate the value of heavy displacement for her size in 'engineless' handling.

We once ran out of gas coming into the marina and drifted all the way into the slip.  I've been on 'light' boats that would have not made it that far via inertia alone.

 

[Chattcatdaddy]

Good point! Something I will have to consider when I`m closer to a buying date.

[tomwatt]

I see the Paul Coble/Bristol Corsair info got posted ahead of me, so I won't go into that except to add that he seemed to have gone off into naval architecture for the Navy after this one foray into sailboats. Myself having succumbed to the lure of defense funding a time or two in my life, I cannot criticize. Destroyers pay better than sailboats anyday.

While I loved the quote about the Scandinavians building boats and seeing them come back, I seem to recall (cannot source this, as it stems from an old college lecture I almost slept through) the Viking craft being built in two modes - the dragon ship whose form we see in museums, etc. that was a flexible ship that is supposed to have given and sprung with the waves, and another craft, a much stodgier merchant/cargo/trading ship that I don't know of any surviving examples of... but might tie into the quote since this was a workhorse shipform for the Vikings.

[Pablo]

One unusual, or at least less common, characteristic of the Yankee 30 is the prop location, extending from the keel rather than in an aperture immediately in front of the rudder (probably accomplished through a V-drive gearbox).  Having the prop so far from the rudder will decrease close-quarters low-speed maneuverability (like when docking), as you can't "kick" the stern one way or another as easily...

Compare this underbody to one of my favorite hulls, the Contessa 32.  Prop right in front of well-protected, skeg hung rudder will give good maneuverability.  I also like the fairly low aspect fin - long enough for good directional stability but with much less wetted surface (drag) than the traditional full keel.  Yes, it's a bit of a compromise, but in this case it seems to get the best of both worlds.  

This might be heresy, but even though I've owned 4 of Carl Alberg's very traditional full keel designs, I think a Contessa 32 might be one of the boats I'd take around the big blue ball...

Exactly! you sight two of the aspects that I dislike about the Yankee 30, the rudder isn't fully protected by a skeg and the prop position. 

  The devil's advocate would say that a boat that points higher is better able to claw away from a lee shore and less likely to ground... and they would be right in some circumstances.

  The bottom line is that every cruiser must know themselves, and and their limits... and those of their ship equally well.

This is always a difficult point, especially with a newer sailor buying their first boat.

[hughesw]

Greetings,

This is my first post on this forum. I've owned my Cape Dory 22 for a little over two years now and I'm still as enamored with her as the first time I sailed her. She is a bit on the small side. She wants to be a Cape Dory 27 when she grows up.

I sail mainly on Lake Sinclair in Georgia, and have made it to the BEER Cruise for the last several years. Hope to do more coastal cruising.

Cheers,

Warren Hughes

[Tim]

Welcome to Sail-Far Warren

[hughesw]

Thanks Tim.

[Chattcatdaddy]

CD22 looks like a pretty capable pocket cruiser. Gonna put that on my list of models to keep a watch out for when I get around to actively shopping.

[CapnK]

Our "eye" for beauty in a boat has developed based on what boats we SAW, collectively over decades (or longer).  Boats that lasted, ie that were seaworthy enough to 'survive' got seen more...so commonness was related to seaworthy, safe design.  

Long overhangs fore and aft, a fine entry, rounded forefoot and other design characteristics developed into 'beautiful lines' from the premise that, subconsciously at least, "hey, there's a SAFE boat...a real SEA boat."

I think it's an interesting idea.  It's not to say other design parameters are less seaworthy, but maybe they have not been around long enough to be 'proven' to our eye at an instinctive level.

This made me reflect that the wide-stern boats of a more modern design come from 'race boat heritage'. Look at the downwind sleds typical of the big races (Open 50's & 60's and the like) - its the same design, carried to an extreme in the case of a racer. Similar to automotive tech, race-course thinking then "leaks" into the consumer end of things...

I'm not sure that the question "Is that good?" can be asked about this; seems to me that there is plenty enough of gray area that that question is moot. But I think that the 'purpose-built design' aspect of those kinds of hull forms need to be taken into account. Long distance, shorthanded cruising by *recreational* sailors is different than the endurance feats performed by long distance, shorthanded *racers*.

The 'old' 'classic' hull shapes, I think lend themselves to a certain amount of 'easier' sailing - less taxing, less of an endurance feat to keep them making the miles, and in conditions when things goes tits-up, they act and react to sea state and weather in a manner which is less taxing on those aboard, and that due to the older style hull shape, rig and general design.

Just some thoughts, pretty incomplete, but perhaps enough to contribute, well, something... Good discussion!

[Captain Smollett]

Saw a copy of SMALL CRAFT ADVISOR today that had a South Coast 21 on the cover.  I immediately said, "That looks like an Alberg designed boat."


When I flipped open to the article, I saw the hull out of the water and saw fin keel and exposed rudder.  Then I said, "uh, now I don't think it's a Alberg boat."

Sure enough, Alberg designed the South Coast 21, and from the waterline up, you can really tell.  It looks quite a bit like a Cape Dory Typhoon (what I thought this one was at first blush).  His original design had the typical Alberg keel, but the fellow that commissioned the design wanted something 'sportier.'  Alberg refused for a while but ultimately gave in ... the article said that he really did not trust the fin keel design (it was still new at the time).

Interesting story...


From the South Coast Owners Association Site:

[Bill NH]

Great-looking boat, Haidan.  I'll bet that doghouse is great in the Pacific Northwest!
Can you tell us more about the design and who built her?  Is she custom, or were a number built?

[SeaHusky]

In another thread I posted a link to a guy who plans to take his Albin Vega around cape Horn and I find this especially interesting because of recent years debate in Sweden about the suitability of the Vega for bluewater sailing. The debate mainly concerns the fact that the Vega, despite a number of Atlantic crossings and even the odd circumnavigation, does not have the classic Scandinavian design but was one of the earliest popular cruisers to get its stability from hullshape (wide, flat) rather than a deep, heavy keel. Those who are critical say it is unsafe and unsuitable while those who approve say "well it seems to work, doesn't it?"
In one of his articles (august 2008) http://thesimplesailor.com/articles.html Roger Taylor claims that his twin keel Corribee is less prone to capsize because the shallow draft doesn't "trip" the boat when forced by a large wave, instead the boat slides sidewas. I wonder if this may be why the Vega works better in rough conditions then it "should".
What do you think?

[AdriftAtSea]

That is very likely.  That is the reason many multihulls do very well in storm conditions, and why you're supposed to retract the boards prior to a storm, unless you're trying to claw off a lee shore.

[Frank]

Avid 'small boat guy-author" Larry Brown found the same. In what were storm conditions for his lil 15...it handled 'cork like' with the board up and did not display the same 'being thrown around' behaviour it did with the board down

[Bill NH]

I never thought of the Vega's 3'10" design draft (actually a good even 4' in the water) as shallow draft.  With its long, low-aspect fin keel it has quite a bit of lateral surface area.  I would doubt that the same affect as a cat or tri pulling up the board(s) is coming into play.

Frankly, I was not impressed with the strength and construction of the Vega I owned.  Compared to my Cape Dory almost everything was lighter, thinner, flexed more and was less well-supported and definitely did not inspire confidence on my part.  The Vega was engineered to cut materials where the designer thought they could be safely cut - that's why a Vega 27 weighs in at about 5700 lbs where a Cape Dory 27 would be more like 7000.  I would not put a Vega at the top of my offshore list despite its reputation.

I honestly believe that many of the incredible exploits that sailors have made in Vegas should be credited to the skill and guts (and good fortune) of the sailors, and could have been made by these same sailors in a variety of boats.  The fact that Vegas can be found in abundance and cheaply all over the world may also have contributed to them making notable voyages, as there are literally thousands of them out there sailing!

[Grime]

Frank,
Did he have any canvas up or was he under bare poles? I have a swing keel and always trying to figure out what is best position up, down, part way down for different conditions.

I would prefer a boat like Tehani but I have what I have.

[SeaHusky]

Bill
As the Vega has only 35% of its displacement in the keel and the slightly shallower draft gives even less of a righting momentum, this is the main argument against its "seaworthiness". The flimsy hull and need for reinforcements also speak against it. As you say, it's recent rise in popularity as a bluewater cruiser is almost completely due to the fact that in Sweden, were most of the 3500 ever built still remain, they go for around 7000$! This means that although it is lacking in many areas it makes the worlds oceans accessible to any 19 year old school dropout. The recent Atlantic crossings and a circumnavigation have been done by people in their early twenties with little or no sailing experience at all which is why the boat seems to have some kind of "hidden" seaworthiness. It is not my first choice either but compared to staying home it might be.
A bit off topic but here's a link to the latest(?) circumnavigation. http://www.runtjorden.com/eng_projekt.php
Check out "Economy". Around the world for 13500$ a head! How is that for go simple, go small, go now"?

[CapnK]

Both of those Vega circumnavigator sites are cool.

Grog fer ya, SeaHusky!

[tomwatt]

You know, I think of my boat as "small" and I often forget that it's got quite a bit of room compared to some. Of course hanging out on Sailnet with the 50-footers will do that I guess. I consider myself blessed with a nice hull.

[Captain Smollett]

(NOTE:  The following post was made in response to a post that has since been deleted.  Without the earlier post, the reply seems completely out of context).

Computer modeling, whether it's the weather, structural engineering, aeronautical engineering, fluid dynamics or whatever, is only as good as the person doing the modeling using the computer as a TOOL.

Therein lies much of the problem that many "lay" people don't appreciate.  There are a TON of people using computers tools that DO NOT understand the models or how to apply them.  So, they run a model, the computer spits out a number or a pretty picture and blammo...the number or picture gets reported/use/quoted/debunked.

I'll give a little case history from just a couple of weeks ago.  I was contacted by a client to do some modeling of something that is VERY dangerous and could have life-ending consequences for both my client and INNOCENT bystanders.

In my reply, I cautioned the client that ANY results we get from our models MUST be thoroughly and carefully tested with real-world, hands-on engineering tests.  The modeling results can guide the process, but it's NOT a 'model this, and go into production' type solution.  The potential costs are too high.

He absolutely agreed and was already thinking on that page.  I like to work with professionals that understand this sort of thing, and only felt compelled to mention it because all too often, the prospective client does NOT appreciate this.

Would you 'ask' a circular saw to build a house?  No, of course not.  Nor should one entrust the results of a computer model, which are nothing but numerical calculations, to provide a solution to a contextual problem.  The computer is only calculating numbers based on the equations it is programmed to use and only using the base data it is given.

Back to the topic at hand....the ONLY conclusion that can/should be drawn by ANY scientist or engineer using modeling is "this model says that cannot be done."  He SHOULD understand that the model could be limited (on purpose) or flawed.  The discussion should then go into "why might this model suggest that" and the thinking, problem solving HUMAN BEING should evaluate the results.

So, yes, there are many cases where a model says something cannot happen (or happens differently than reality).  That's often not the fault of the model itself or theory upon which it is based.  Rather, it is either (a) the fault of the USER applying a model in an incorrect context or (b) there is something unknown that the model is not taking into account.

Further, that's how models are improved...just like any other science, it is the FAILURES that teach you more than the successes.

Just some near-random thoughts from a dude who does the following professionally:

Quantum Chemistry Modeling
Molecular Dynamics Modeling
Computational Fluid Dynamics
Reactive Flow (Detonation) Modeling