Why I'm Following Sven Yrvind

[CarlosK2]

CF: Center of Flotation
CG: Center of Gravity

(A) 10 sqm per Ton: A yacht that is slow relative to the speed of the ocean wave approaching from the stern: good longitudinal balance

(B) 20 sqm per Ton: A high-performance sailboat—fast relative to the wave speed—true to the finest tradition

 

[CarlosK2]

We can achieve exceptional pitch control:

a) By aligning the Center of Buoyancy with the Center of Flotation, we eliminate 60–90% of the problem caused in the past (circa 1880) by "heavy quarters"—which would submerge the bow when heeling—and its modern equivalent: wide sterns.

b) Placing the Center of Gravity aft of the Center of Flotation, thereby eliminating the tendency for the bow to bury itself when facing following seas.

c) With a lightweight 6-meter boat, we can achieve a longitudinal metacentric height that is—let's say—astronomical: 18 meters (3 x LWL). This means that a 1-degree pitch down by the bow shifts the Center of Buoyancy 30 cm forward (5% of LWL).

d) Hydrodynamic trim—bow up, stern down—upon acceleration (Froude number ≥ 0.50)

This results in two sailing modes: high-performance sailing with high pressure under the bow (hydrodynamic lift), and the stability of a classic balance for low initial speeds.

In other words, the boat can begin to surf driven by either wind force or the push of a wave; the surfboard performs well even when carrying only a staysail reefed to 3 square meters and centered, with the rudders lashed and the young adventurer safely inside the cabin.

Thus, we have a fun sports boat that, in a survival storm, transforms into an "Yrvind-style" survival capsule—albeit one with a more civilized and habitable cabin.

 

[CarlosK2]

Passive safety

Passive safety features of Yrvind's grandson's modern, sporty, and fun capsule:

A) Impact against a semi-submerged container full of Chinese electronics or a playful Iberian orca

the capsule’s bow and stern are completely separated by the major bulkhead at station 6 (dividing the cabin and cockpit); it features 30 watertight compartments, with those in the bow filled with low-density material

B) Lateral impact from an especially savage wave—three lines of defense:

First line of defense: a very low chine in a light boat and good freeboard allow the capsule to slide sideways at 60 degrees

Second line of defense: 90 degrees—a beveled upper section prevents the deck from catching the water and tripping the vessel

Third line of defense: 110–130 degrees—rapid righting after a capsize, thanks to the combined action of a large keel and a large, fully enclosed spruce mast

The young adventurer sleeps atop the chart table—measuring 2.40 meters long by 60 cm wide, except where the mast is stepped—with cargo drawers for food located underneath:

 

[skaraborgcraft]

I heard it is good to get the head at the centre of movements to reduce sea sickness, but im always sick for a couple of days, HEAVE being the operative force of which nothing can be done.

I believe "Sopranino" and "Trekka", had "bevelled deck-hull transitions. Almost as cool as the rolled decks on the Fairy Atalanta.

 

[CarlosK2]

Yes, indeed.

In ocean sailing, a few days of discomfort are perhaps inevitable; I prefer coastal sailing—it’s more pleasant and scenic, sailing and then dropping anchor. But the small ocean-going boat is an obsession of mine, and I believe my proposal offers a great solution: a 1 Ton WindSurf Board Plywood Epoxy in the best Swedish and British tradition Thomas Harrison Butler in Memoriam: a boat that is easier to handle and safer, yet comparable to a sports yacht costing 300,000 euros. For once, the universe is on the side of the little guys. A sailboat weighing under 1 ton can be spectacular; you couldn't achieve those same figures and the freedom and ease of hoisting and dousing square meters of sail in a larger yacht even with 4 million euros. It comes down to the square-cube law. That's why I don't see any point to Yrvind's sarcophagi.

The bevel between the deck and the topsides is a good idea: both C.A. Marchaj and Claughton—working in the Southampton wave tank—highlight the critical moment when the water bites into the deck and trips the boat up.

 

[skaraborgcraft]

. It comes down to the square-cube law. That's why I don't see any point to Yrvind's sarcophagi.

Its all Sven talks about when it comes to strength, but he very much disliked my comment of "as much room as a phone box". Sven believes suffering is part of the journey. Been there done that, and going without hot food or drinks in the Southern ocean, does not make any sense. 1000 T-bags do not take up much room and the morale benefit is off the chart. Each to their own.

 

[CarlosK2]

I think the ratio for evaluating performance sailboats should be as follows:

square meters of sail area hoistable in absolute comfort downwind (let’s not forget a crew member was killed by a rudder blade after falling overboard while retrieving a gargantuan gennaker) / yacht tonnage (calculated without too much fudging)

calculated this way:

the 'cheap' European performance boat, €180,000: 30 square meters per ton

my windsurf board: 50 square meters per ton

 

[CarlosK2]

And then there is the matter of condemning young adventurers to a chastity more rigorous than a monk's.

On my ocean-going windsurfing board, the young adventurer sleeps or rests atop the huge chart table, with his ribs well protected.

Buuuut once the destination is reached, there is a gigantic bed in the bow.

 

[HelmutSheina]

Its all Sven talks about when it comes to strength, but he very much disliked my comment of "as much room as a phone box". Sven believes suffering is part of the journey. Been there done that, and going without hot food or drinks in the Southern ocean, does not make any sense. 1000 T-bags do not take up much room and the morale benefit is off the chart. Each to their own.

It seems a lot of the time it isn't the boat that gives up but the crew. I like to have a vacuum flask as sometimes the opportunities to boil water are scarce. We used to have insulated pint mugs with an extra wide bottom that did the trick for hot and cold beverages but haven't seen them in 20 years.

 

[CarlosK2]

You pay 180,000, 240,000, or 300,000 euros and don't even get a damn seat; I’ll only look at the brochures again when Mercedes SLK—Sportlich, Light, Small ("Kurz")—models start being sold with bar stools.

Both the young adventurer and the old man on my windsurf board ride comfortably, feeling a pleasant sense of security as the wind picks up and the waves grow.

The mainsail luff rope is just 40 cm away.

I can even caress the mast.

The 3.1-meter bowsprit pivots aft and comes right into the sailor's hands.

Mind you, you do have to get up out of the seat—what cruelty on the part of the designer.

Long live functional pleasure; down with the glorious tradition of "the lash, rum, and sodomy."

 

[CarlosK2]

You arrive at your destination and drop the anchor without ever leaving the cockpit—such are the perks of a tiny, light sailboat.

You pull up the twin rudder blades and slip on their canvas covers.

Using an electric screwdriver, a winch, a 4x4 = 16 block-and-tackle system (a variation of the "Double Spanish Burton"), and leverage, you hoist the massive weighted centerboard; and it rests out of the water, cradled in a canvas sleeve, with its leading edge sitting 5 cm above the cockpit sole.

And the "one-ton windsurf board" floats in mere inches of water.

From my perspective, it is a waste of resources and potential to squander the functional advantages of minimalism by shutting yourself inside an Yrvind-style Egyptian mummy sarcophagus.

 

[CarlosK2]

It is interesting that, due to the difference between industrial and artisanal production, that small attachment for the electric drill used to cost as much as—or even more than—the electric drill-screwdriver itself; nowadays, you can find it for around 20 euros.

(Achtung: one hand on the drill, and the other hand—crossed—on the electric drill's battery.)

 

[CarlosK2]

5.7 to 6 meters is an optimal size—a shame to waste it.

Going smaller ... less is less

the displacement-to-length ratio jumps upwards, the human body cannot be shrunk; a 2-horsepower outboard weighs the same regardless, as does a liter of water or a kilo of food.

An ocean-going yacht simply cannot be smaller—bear in mind that the displacement of "Yankee Girl" (1979) (10'0") [!] was 2,200 lbs at the start of the voyage.

If we want the pleasure of gliding over the water, then a goal worth striving for is ensuring that the fully loaded boat—carrying, for example, food for 90 days, 60 liters of water, and 48 liters of other liquids—does not exceed a displacement-to-LWL ratio of 150.

Furthermore, reducing size causes the longitudinal metacentric height to plummet—a highly valuable attribute; in fact, instead of measuring yachts by length, we could measure them by meters of longitudinal metacentric height.

Going larger... less is more.

And that is an opportunity not to be missed.

A small size allows for Upwind Power—because in a small, light boat, the effect of taking on seawater to windward is immense—as well as Downwind Speed

And speed equals comfort, as it reduces rolling, both through speed itself and the chosen course. We can escape the "dead run" (wind directly astern)—where the mainsail is lowered and two headsails are set, one on each side (a strange, uncomfortable sailing configuration not even used in the 19th century)

After all, Yrvind aims to achieve the same goal as the industry-standard yacht when crossing an ocean: "dead run"

 

[CarlosK2]

I insist: for once, the Universe is on the side of the little guys.

Upwind: a boat generating 400 Newtons of forward thrust transforms into a little monster producing 900 Newtons when it takes on 220 liters of seawater.

Downwind: thanks to the square-cube law, we get a machine with a ratio of 50 square meters per ton for the coastal version, and 40 square meters per ton for the oceanic version.

It drives me crazy that whenever the topic of small ocean-going boats comes up in forums, the conversation inevitably turns to drifting buoys, barrels like the one used by the woman who went over Niagara Falls, or Egyptian mummy sarcophagi—the Yrvind style, or—why not say it—the Roger Taylor style.

I believe the inspiration drawn by our forebears in the "church of minimalism"—looking toward survival capsules or cabins in the dark woods—can be reinterpreted as an efficient exoskeleton in the form of a high-performance, powerful windsurfing board.

 

[CarlosK2]

and Reaching

Reaching on a performance sailboat is magnificent: a tiny change in heading lets you feel the immense power of the wind, yet bear away just a few degrees and the beast calms right down.

It is just right for those of us who want to avoid scares but still crave a bit of excitement—a touch of spice, so to speak.

My impression—or rather, my firm conviction—is that many people fantasize about a slow ocean crossing because they associate it with tranquility. In reality, there is nothing more uncomfortable than a slow sailboat. Well, actually, there is something worse: a racing sailboat with a large crew; to my surprise, there are people who pay to endure that experience.

Upwind power, surfing Downwind, and playing the wind while Reaching...

That is what a sailboat is all about. To me, a sailboat weighing more than a ton makes little sense; it either performs worse as a sailboat, or you lose freedom and ease of mind.

Ultimately, I increasingly understand those who opt for a motorsailer or simply a motorboat.