Sail fast & Sail flat

Originally Posted by Parati

I think the 200 avg is construed to mean every day all the time which I do not intend to imply, more like can the vessel achieve 200 avg when the conditions are right and if you look at the Ourson 60 polar on a reach you theoretically could hit 336 miles in 20kn at 140deg in 24hrs. Throttled back 200 is very realistic in the same conditions taking it easy.

No, it is not as you like it to be.

Don´t you read what we write?
Even a 80ft mono does rarely 200miles a day, on ocean passages. A 50ft* never. There are occasions when this could be achieved for one day, yes, but on long trips with family crew, you will most likely never see it happen.

The class 40 boats, actually racing the Route du Rhoum, give a nice impression about what we are talking. The leader did some 7,7kn average over 2.500 miles at present. Raced 24 hrs a day!

Read this article, and digest it slowly.........................

Richard
*and not the average 50ft Cat either!

[larry larisky]

i read the Pete Culler book about his spray, she sailed quite flat as he wrote in his book.
i have to buy the slocum book. i am attracted by this kind of boat, but i will say for coastal cruising.
i like the heavy construction, and i will sheath in zinc, like the old fishing trawler.

[tspeer]

Originally Posted by Parati

Is it possible to build a monohull cruising sailboat under 50' for shorthanded crew that does not pound, sails fast (200+ avg days), and sails flat (less than 15% heel)?

Having followed the thread, and going back to the original question, I think the answer is, "No." The specification drives the design to be a multihull, probably a catamaran.

200 mi averages means speeds certainly above 10 kt, and probably a capability of speeds above 15 kt over 500m. That requires a high powered boat.

In order to carry the sail for double-digit speeds with less than a 15 degree heel angle, the boat must be very wide. A keel simply doesn't have much leverage at small angles. The stability has to come from form stability.

A wide monohull will slam. In order to avoid pounding, the hull(s) must be narrow. You need a wide beam overall to meet the performance requirement with a narrow waterline beam to meet the ride quality requirement.

So it has to be a multihull. Nothing else will meet the performance specification.

You have a choice. You can go with monohull esthetic sensibilities, or you can have the desired performance. Quite simple, really.

[michael pierzga]

Have not doubt that a Multihull slams !! Ive heard them a half mile away as they take a terrific beating tyring to motor thru a narrow passage upwind. Every boat pounds when you put its nose into a 2 meter hole.
Nothing wrong with multihulls if that what you want....for there length even the cruising cats are faster than a mono of similar length..and more room. Those Bill Lee type west coast, long and thin, monhull..Fast is Fun.. are also very worthwile to consider. The most important long term goal of a yacht is to look good...those west coast fast is fun boats..LOOK GOOD.
I recently saw the whole fleet of TP52 speedsters out of the water. These boats boats achieve very high speeds in all wind angles, but would be impossible to sail as a dual purpose boat.
Probably the best approach would be to solicit study plans from few different designers for the pure sailing machines that you like. Take the study plans and with thought , carefully modify them to meet your specs. Draw your own boat. Once you have the Finot or Judel Vrolik or Lee study plan optimised for your use, take it to a naval architect and have him comment on your concept. This is how many great boats are conceived. Once you have your perfect design take it to a boat builder and have him comment on whether the boat is buildable. Once you start to rely on Carbon and various other highly engineered difficult to use hull materials and techniques to achieve your concept you might have conceived a boat thats impossible to build for the normal guy. The little pogo ,as far as I know, has no carbon and is very simply engineered. The little Beneteau Figaro speedster is also a very simple hull that will stomp on any dual purpose boat in its size range offshore. .

[FAST FRED]

A look at the polar graph shows to get 200nm days the wind required will need to be 20K plus , every day all day.

The internal comfort level will suck , the sail area and size will be over 400sq ,each , about the limit on a mainsail for one crew .

In light (under 20K ) winds the engine will be on to get the days run.

The Steve Dashew 64 ft motorboat would probably be a better choice for high speed , comfort underway and in port.

Toss the sail, or settle for 120nm /day.

FF

[larry larisky]

i will be afraid in a multi hull, because of my lake of knowledge of these boats.
but they seams efficient and proven good for cruising.

[FAST FRED]

"i will be afraid in a multi hull,"

Good idea , as they are as stable inverted as upright.

FF

[Stumble]

Sadly Fred mutli-hulls are generally more stabe inverted than right side up. That being said, the conditions that would flip a 45-50 foot mutli-hull over are pretty likely to be life threatening conditions on any boat. The trick is to avoid those conditions that cannot be reasonably handled.

[FAST FRED]

For years I have been working on a,

"Dial a Wind" that runs on a 9v battery , and you simply dial the wind speed and direction desired.

When its done ,

"The trick is to avoid those conditions that cannot be reasonably handled."

I will start on the "Rogue Wave Chaser" that creates a 200 mile clear zone , with no big cat upsetting waves.

FF