Why I'm Following Sven Yrvind

The big difference between the prodigious classic 300 D/L surfboard of Roman Sanchez, an old Baroudeur, and my modern 150 D/L surfboard is Upwind

 

Why does my boat Surf so fast

Sagitta 30 vs. Shuttleworth 31

Why does my boat surf so fast? https://www.boatdesign.net/threads/why-does-my-boat-surf-so-fast.50195/

Obviously there will be two other small differences

In "Surf Gliding" (with big Atlantic Waves) my light board will run faster in the valley than Román's heavy board; but "Surf Gliding" towards the center of the earth, Román's heavy board will reach a higher speed tip.

But these are nuances and details to talk about.

The great thing is that both boards (Classic and Modern) have good behavior and are safe, comfortable and pleasant and not a nightmare for the helmsman.

The other detail is that my board started "Surf Riding" with very small waves of half a meter and maybe 30 centimeters when the Wave of the Sea destroyed the 0.5 Froude hull wave.

 

The other issue is the pleasure of functionality

In this convertible sports car of mine, i sit comfortably and safely with a 55 centimeter backrest, i have the mast at hand, i don't have to leave the cockpit at all, and nothing is nothing: not even to set the two anchors (the anchor for sand and mud and the sea anchor)

and the interior is comfortable for a grumpy old man and not the typical 1964 French style.

 

And hove-to like a Yawl

 

In port the daggerboard and rudder blades sleep out of the water and are kept clean.

And the sailboat can approach a beautiful Atlantic sandy area like a catamaran.

 

let's see what's closest to my creature

(1) The interior is the typical French one from the 50s and 60s and to which i am very accustomed: the bow area is useless: to get there you have to cross the mast, the daggerboard, and to make matters worse, the ridiculous galley and the funny little table of charts (?) that serve no purpose, only to get in the way. In my creature the chart table and galley area measures 1.6 meters x 60 centimeters.

(2) You come down dripping water and you have already soaked the bunk beds useful for sleeping. In my creature you enter soaked and do not wet the bed, and there are two good places 60 cm wide to hang clothes: one for hanging dry things and another for wet things.

(3) Exposed cockpit and exactly the same as the current yachts that for 180-300 K Euros do not give you a single fuxxx place to sit comfortably

(4) Questionable passive security.

(5) it has no planned procedure for safely standing still. My creature has two: hold like a yawl, and bow to the waves with a sea anchor.

(6) Upwind. My creature is +150% more powerful and thus capable of overcoming the aerodynamic resistance of the heeled hull.

 

Surf Riding will be the same or very similar. These little Plywood ones are a delight

My creature has an advantage: the StaySail is on its boom, and on the other hand the Jib is very comfortable to hoist: the bowsprit, a carbon tube, the mast of a WindSurf board, pivots towards the stern and reaches the hands of the navigator. Of course: the navigator has to leave the comfortable seat and stand up. A cruelty of the designer.

 

Loading 200 liters of seawater, a 1 Ton sailboat is converted from a 400 Newtons boat into a 800-1000 Newtons boat.

The sailboat can continue its course at 5 knots close to the wind (Windex = 30) or, as is typical in these cases, with a real/true wind speed of 25 knots at 10 meters high, give way 5 degrees (Windex = 35) and advance at 6 knots.

LWL: 19.64 feet

 

another small nuance or detail

Román Sanchez's magnificent and extraordinary heavy Surfboard ...

an old Baroudeur 19.19 feet LWL

reached a top speed of 20 knots

buuut it also swallowed some waves

i mean that my light Surfboard is quite likely, if not almost certain, to surf most of the waves

 

1- Please stop being dishonest by claiming that I am being contradictory. I am NOT - I am merely discussing the effect of the inevitable tradeoffs in yacht design. Only a fool would say that one cannot defend a design feature from some aspects and yet point out its issues in another aspect.

Please stop being dishonest by claiming that I am using "superstition and bar opinion". I spent a decade working in the industry full time and have since worked part time and studied the social construction of boat design at university. This has allowed me to interview some of the best naval architects and sailboat designers in the world, on the record and often in taped interviews or correspondence. I have been lucky enough to interview Julian and Frank Bethwaite (who I've known for decades), Paul Bieker, Nigel Irens, Russell Bowler, Tony Castro, Andy Paterson, Phil Morrison, Bruce Kirby and many others including top windsurfer designers.

It is a lie to say that passing on information from top designers and NAs is "superstition and bar opinion". People like America's Cup naval architects do not deal with superstition or bar opinion, and I am merely passing on their wisdom.


2- I am NOT trolling, you are merely ignoring the written word. The extreme wedge shape has positives in some ways, such as increasing hull volume aft and permitting narrow entry angles and providing good stability. It also has negatives, such as often creating problematic handling downwind at speed.

What I said when defending the "wedge" shape against your criticism was that "arguably it's very good sense to sacrifice some aspect of performance in order to increase accomodation." I therefore clearly acknowledged that the wedge shape sacrifices some performance aspect. It is dishonest of you to claim that I am being inconsistent.

I'll try to put it as simply as I can - the wedge shape has some good points but it often gains them at the cost of downwind handling. It is therefore perfectly logical to defend the choice of the wedge shape in terms of a boat design overall but to also say that an extreme wedge may handle poorly downwind.


3 - Going from the doodled designs you show, your boat is very different from the design of boats like the Dehler 30. You appear to be looking at the Dehler 30 from one angle only - the plan view. That is ignoring the boat's sectional shape. The pic below is the stern view of the Dehler 30. Note that the sections aft are wide but quite curved. That shape means that the Dehler is not as much a wedge shape as it seems when looking only at the plan view, and not as much a wedge as in your design. The Dehler also has a rising chine line with a much less acute change in section at the chine.



The same applies to Mini 6.50s - they have curved sections aft with flare and a rising chine line.



Some dinghy classes, mainly Moths and UK Cherubs, used flat bottom sections and vertical topsides similar to your design, in what is sometimes called the "coffin shape". It works well at times but when heeled it becomes very problematic because of the angle of the chine and the assymetry. This is not bar talk, this is the actual experience of users including top designers.

Have you ever sailed a boat with the extreme wedge shape of your design? I have, and I've actually owned one similar in shape. So you are being dishonest and silly when you claim that my posts are based on bar talk - they are based on information from experts and from actual experience.


4- You keep on saying that your boat will act like a windsurfer but since you won't reply to a simple question about whether you have windsurfed, I will assume you have not. You clearly do not understand why windsurfers are shaped the way they are because your boat is very different in shape and contains features that actual real-world experience in windsurfers shows to be very problematic at times.

Have you ever sailed a windsurfer with a shape like your design? I have, and I've owned some that were similar in shape. So you are once again being dishonest and silly when you claim my posts are based on bar talk - again, they are based on information from experts and actual experience.

5- You have said that other designer's boats include features that are "useless", "silly", "complete madness" etc etc etc. You throw around a vast number of insults and yet it seems that you cannot take any criticism of your own designs. That's a very hypocritical way to behave.

By the way if you are the great designer you claim to be, how come you're so short of money at your age that you are finding it hard to afford a small boat? Surely if you were as good as you claim you'd have a pretty good income from your outstanding designs and could splash some cash?

What sailboat design and sailing experience do you actually have?