Pocket cruising boats

Data for Dehler 29:
D/L = 163,43
SA/D = 21,98
6*HP/D = 11,09
HSPD = 6,87 kn
CSF = 2,09
MCR = 17.97
AVS = 138,75

Somewhat light and overcanvased to my taste. I find it more a cruiser racer than a proper cruiser.

Windvang: Tomorrow I'l analize Hunter Channel 27 and Pilot 27. Today I'm tired...

 

I think Michael is entering a kind of contradiction here. Increasing ballast and lowering it, being bulbs the extreme case, increase the moment of inertia and so the ability to resist rolling, as well as capsize.
Maybe we are not discussing the same things: On one side there is the usual comparison of a deep wine glassed classic hull with a low center of gravity, against a same displacement boat with flatter sections, 'normal' shaped keels and higher overall CG. In this case, yes: The wine glassed typical hull resist better capsizing than the second. But when talking about extreme cases like bulbed keels, CG becomes lower than in the classic hull case and inertias are also bigger, so this last boats are safer (Again: If keels don't break)

Once again: A dismasted yacht with a long bulbed keel is quite difficult to turn down (not impossible, for sure) even having lost mast . Although inertia diminishes, absolutely, continues to be pretty big. Other keel configurations are more prone to capsizing in big waves when dimasting.

We'll do that. But Jeff already has promised to open an stability forum within next days: Let's wait and do it there.

 

A lot of stability data can be found at the RYA site.
http://www.rya.org.uk/NR/rdonlyres/...E-07F31E275320/0/StabilityWebPage07_10_05.pdf

 

Yes and I will wait till that happens to reply to you. The point that you want to discuss is probably the most important, most controversial and the least understood of all issues related with a sailboat stability and design parameters, regarding seaworthiness and safety .

It will be a good opening thread to that forum

 

Guilermo you should look at swedish folkboat, it is a vonderfull small cruiser, and it is extreamly seaworthy. I don't know any numbers now, but I'll try to find some.

 

Folkbåt is a handsome and safe cruiser!

LÖA: 7.68 meter
LWL: 6.00 meter
Bredd: 2.20 meter
Lägsta fribord: 0.568 meter
Djupgående: 1.20 meter (Draft)
Segelarea: 16 kvadratmeter (measured sail area, triangles)
Segelyta (verklig): 24.00 kvadratmeter ("real" sail area)
Deplacement: 2000 kilogram (designed(?) displacement)
Kölvikt minimum: 1000 kilogram (Ballast, minimum)
Kölvikt maximum: 1057 kilogram

 

My friends sailed one from sweden to Lithuania. Wind was blowing about 10 knots and they haven't used their wetsuits! Although space inside is limited, but the simplicity of the rig, and pleasure of sailing such a boat is enormous. Short trip with this boat was many times more exiting than sailing an old 42 feet IOR racing boat

 

Lovely boat. First unit launched on April the 23th (1942), a day when important births happen, like the ones of King Afonso II of Portugal, W. Shakespeare, Shirley Temple, G. Gefaell, etc....
A pity there are none (to my knowdlege) in this part of Spain. And they even cross oceans....
http://www.jesterinfo.org/BlondieHasler.html
A link to her history: http://www.sfbayfolkboats.org/history.html

Assuming Disp = 2000 kg, ballast 1057 kg (thanks, Raggi), 16 m2 sail triangles, and a 10HP engine, here some parameters:

D/L = 258,26
SA/D = 10,24
6*HP/D = 13,6
HSPD = 5,95 kn
CSF = 1,76
MCR = 22,81
SSV = 11,6
AVS = 359,24 :!:

If we use 24 for sail area:
SA/D = 15,36

 

I once sailed a grp copy, an IF Boat, for a week on the Norwegian southern coast.
It's a very safe and comfortable boat for cruising, it can steer itself for a while and the motions are relatively slow.

http://www.ifboat.com/indexe.htm

 

Guillermo, regarding 27ft sailing boats stability curves, searching in the info I have available, I can not find anything, except the one from Hunter channel 27.

But I have several from 30ft boats, light and heavy. Perhaps we can change to 30ft? They are small boats, regarding ocean seaworthiness.

Meanwhile, while searching I have found this beautiful 27ft cruiser.
Look at the speed data (from a test) on the image from Yacht magazine.
You don't need a fat boat to go fast, especially upwind

http://www.cafe-yachts.com/gallery_c27constr.htm
http://www.cafe-yachts.com/gallery_c27sail.htm
http://www.cafe-yachts.com/gallery_c27design.htm
http://www.cafe-yachts.com/

 

What the hell is an AVS of 359,24

 

Two examples of rather traditional styled boats, from the Glen L designs website:

The 29' "Sir Francis Drake"
http://www.boatdesigns.com/products.asp?dept=424

The 22' "Amigo"
http://www.boatdesigns.com/products.asp?dept=423

These are both off-shore capable designs...

 

Cafe 27 and 24 are reasonable priced boats with a modern look and traditional (polyester) construction. I think they give a lot of boat for the money.

 

Vega said,
"What the hell is an AVS of 359,24"

I understand that to be “angle of vanishing stability”. But the number is too large compared to other boat I have looked at.
Robert Gainer

 

I know that Robert, but the AVS only goes to 180º. A boat with a 180ºAVS is a boat that will never stay upside down. It is a boat without negative stability.