August 26, 2010

The magical centerboard

I WAS SAILING a dinghy the other day and thinking what a clever invention the humble centerboard is. In some ways, it’s the equivalent of a wing on a plane, but on a boat it’s a mostly invisible part of the magic of sailing.

I say magic, because the centerboard, like a fin keel, stops a boat making leeway by making leeway. That’s right. If a centerboard didn’t make leeway of between 3 and 5 degrees, it couldn’t work. It wouldn’t provide the “lift” to stop a sailboat drifting off to leeward so fast on the beat that it would never be able to make way to windward. And it has to be moving forward through the water to provide lift, of course, otherwise it will be stalled and allow the boat to slide sideways.

According to The Oxford Companion to Ships and the Sea, the centerboard for small craft was invented in America in colonial times. “The need to be able to sail to windward close-hauled, with an entirely flat bottomed work boat arose from the great stretches of shallow waters found in the Chesapeake Bay and along the Atlantic seaboard from Long Island Sound to Florida, and so the centerboard was born.”

Although some famously successful ocean racing yachts have had centerboards, naval architect Ted Brewer says the pure centerboard cruiser has fallen out of favor now, although it still has much to offer the sailor.

If you’ve sailed with a pivoting centerboard, you’ll know how useful it is in balancing the helm by moving the center of lateral resistance forward and aft. If you raise the board partly to angle it aft, for instance, it greatly reduces the tendency of a sailboat to round up while on the dead run.

To take this a step further, some boats have two centerboards, one large one up forward, and another smaller one aft. The task of the forward board is to reduce leeway, while the aftermost board is raised or lowered to attain neutral helm. This is particularly handy in heavy weather, when the changes to sail balance caused by reefing can by compensated for by adjusting the boards.

Like a fin keel, the efficiency of a centerboard usually increases with its aspect ratio. The longer and thinner it is, the better it will perform, especially if it is given a streamlined shape that provides more lift for its area.

It seems so simple when you look at it. You simply stick this piece of board down into the water through a slot in the boat and it stops you going sideways. But if you care to think about it, there’s a lot of interesting science and hydrodynamics going on down there. Like many aspects of sailing, we don’t normally give it much thought. It just works when we want it to, and that’s that. But it’s magic all the same.

Today’s Thought
‘Tis frivolous to fix pedantically the date of particular inventions. They have all been invented over and over fifty times. Man is the arch machine, of which all these shifts drawn from himself are toy models.
— Emerson, Conduct of Life

Boaters’ Rules of Thumb, #88
Fuel consumption, diesel. An inboard four-stroke diesel engine consumes about 1 gallon per hour for every 18 horsepower used. In other words, a 36-hp diesel running at full throttle will use 36/18, or 2 gallons an hour. That same 36-hp diesel tootling along slowly and developing only 9 hp will use 9/18, or 1/2 gallon per hour.

Tailpiece
“What happened to that guy who tried to cash your check?”
“They took him away in a strait jacket.”

August 24, 2010

Beware the barnacles

(Come back every Monday, Wednesday, Friday for a new Mainly about Boats column.)

IN THE WAKE of the Great Egg Recall, the Food and Drug Administration is warning boat owners that certain species of barnacles may now be infected with a virulent strain of salmonella. Widespread reports from marine repair facilities on the East and West Coasts indicate that groups of affected barnacles — known as barnacella — produce acids that can damage wooden and fiberglass hulls.

Twenty mysterious sinkings, originally blamed on polyestermites, have now been ascribed to barnacella acid that ate through the boats’ hulls under water. More sinkings are expected as the disease spreads.

Insurance companies are warning that barnacella sinkings are not covered under the terms of regular yacht policies. “Even if you have an all-risks policy, we regard this as an Act of God, and therefore we reject liability,” an industry spokesman said.

The FDA urged boatowners not to panic. “Only wood and fiberglass boats whose hulls have barnacles will be affected,” the agency said in a press release issued late yesterday. “We are devoting our full resources to investigating this unfortunate outbreak. Meanwhile we recommend that all boat owners inspect their bottoms for barnacles and boil them if necessary.”

Today’s Thought
Whatever befalls in accordance with Nature should be accounted good.
— Cicero, De Senectute

Boaters’ Rules of Thumb, #87
If it ain’t broke, break it before you fix it.

Tailpiece
“I saw you smash that clock, sir, I’m arresting you for killing time.”
“Nonsense, officer, it was self-defense. The clock struck first.”

August 22, 2010

Experience vs. wallet size

(Come back every Monday, Wednesday, Friday for a new Mainly about Boats column.)

IN THESE FINANCIALLY PARLOUS TIMES, you have to wonder what standards the sailboat charter companies set for their customers. I mean, what sort of skill and experience do they expect from a would-be hirer? Some cynics might suggest that very few customers are turned away these days for lack of sailing ability. They believe that the thickness of your wallet more than compensates for your weakness in anchoring.

But I’m not so sure. Last time I chartered in Grenada the charter company was quite strict. They made me list my sailing accomplishments before they would hand over their nice yacht, and to tell the truth my list seemed quite meager until I remembered that at one time in my life (albeit for a very brief period) I was a professional seaman — that is, they actually paid me money.

It happened when I was young and adventurous. I was looking for a cheap way to get to Britain. I found a Union-Castle liner called the Warwick Castle that was heading that way and hopped aboard. I washed dishes and changed bedclothes all the way to London.

When I say I washed dishes that’s not quite correct. I learned from my fellow crewmembers that the correct thing to do, after fetching meals for the little messroom I served, was to throw the dirty dishes out of the galley porthole. I then picked up fresh clean dishes from the Tourist Class galley dishwashing machines.

I didn’t reveal to the charter company the exact nature of my professional seagoing experience in case it might confuse them. I didn’t actually mention that I was a member for just three weeks of the British National Union of Seamen (Catering Branch), because that’s like telling a prospective employer that you’ve got a BA, Calcutta (failed). It doesn’t disclose the full extent of your skill and experience.

No, I merely alluded to the fact that I had served time at sea as a professional. They were won over immediately. It seemed that not many of their prospective customers could produce such desirable credentials. So they cheerfully handed over their nice yacht, and June and I disappeared northward into the warm blue Caribbean Sea with happy grins on our faces.

Today’s Thought
Experience is a hard teacher because she gives the test first, the lesson afterward.
—Vernon Law, Pittsburgh Pirates pitcher

Boaters’ Rules of Thumb #86
Sailing on Friday. If you are a superstitious sailor, as many of us are, you won’t want to set sail on a Friday. The rule is that you should start your voyage a day or two before, proceed a mile or so, and then be forced to return to make repairs to a turnbuckle that has come unscrewed — or for some other reason calculated not to insult the intelligence of the gods of the wind and sea. Then you can set sail for real on Friday because you’re not setting sail, you’re merely continuing a voyage started previously.

Tailpiece
Then there was the Oriental wife who was most distressed because she produced white twins.
“There, there,” said her husband comfortingly. “Don’t worry about it. Occidents will happen.”

August 19, 2010

Faster under water

IT HAS COME TO MY ATTENTION that certain scientists are now studying animals that have been moving through fluids like air and water for millions of years. They want to know, for instance, why a dolphin can swim faster than a yacht. Well, actually, they may also want to know how to make planes and missiles and torpedoes and warships go faster, but it’s the yachts that should interest us most.

We suspect that dolphins swim so fast because their skin has special properties. But we can’t build boats like dolphins because ... well because we don’t know how to; and besides, I don’t know if you’ve ever seen the inside of a dolphin but it’s not the kind of place you’d like to inhabit for long. It’s kinda messy and smelly down there.

If you’re looking for a faster sailboat, I believe the answer is a submarine yacht. As you undoubtedly know, when a conventional displacement yacht gets up to hull speed it becomes trapped in a large hollow wave. It can’t climb out. And large hollow waves go very slowly. Grandma can pedal faster on her tricycle.

Now, there is no wave under water. Well, there is, but it’s a different sort of wave. We all know that submarines can go much faster under water than on the surface. So what comes to mind immediately is a submarine yacht with a mast and sails.

Aha, you say in your usual perspicacious way, but what about stability? Won’t the submarine yacht just roll over on its side? Well, on the surface, a yacht’s center of buoyancy steps out sideways as the hull heels, restoring equilibrium by shoving upwards to counterbalance the center of gravity shoving downwards. But what keeps a submarine upright? The usual suspects: buoyancy on top and ballast down below. But it must be neutral buoyancy, of course, otherwise the submarine will either pop out of the water like a balloon, or drop to the seabed like a stone.

But never mind that for the moment. Here’s the real thing – is there a submerged sea animal with a mast and sails that the scientists can study? Well yes. As a matter of fact, there is. How about the humble Portuguese man-o’-war, then? Yes, yes, I know. It’s kinda slow and can’t sail upwind. But it’s a good place to start. And it might be better to start slow with submarine yachts, anyway. After all, submarines can’t see where they’re going, which is very worrisome when you’re doing 40 knots under water.

Today’s Thought
The best scientist is open to experience and begins with romance — the idea that anything is possible.
— Ray Bradbury, LA Times, 9 Aug 76

Boaters’ Rules of Thumb #85
Size distortion in fog. With visibility in fog between 30 and 150 yards, vessels and other objects appear twice as large as normal. This illusion also doubles their speed of approach, which greatly raises the heart rate of the skipper

Tailpiece
“She told me you told her the secret I told you not to tell her.”
“Aw gee, I told her not to tell you I told her.”
“You did? Well for goodness’ sake don’t tell her I told you she told me you told her.”

August 17, 2010

The beauty of lapstrake

(Mainly about Boats: a new column every Monday, Wednesday, and Friday.)

A READER CALLED JONATHAN in Fort Lauderdale, Florida wants to know what I think of lapstrake planking. “I was recently visiting in New England and saw lots of lapstrake wooden boats,” he says. “What’s the advantage?”

Well Jonathan, the first thing is that it’s beautiful. If you like looking at pretty girls, you’ll like looking at lapstrake. It emphasizes all the curves. That’s not actually why boats were built with overlapping planks, or strakes, in the first place, though.

Because each plank overlaps the one below it, the thickness is almost doubled along each edge. That makes it very stiff and strong — suitable for one-design racing dinghies, smallish fishing boats landing on beaches, or ship’s launches that take a good pounding. And because it’s so strong, a lapstrake (or clinker-built) hull is normally much lighter than it’s carvel-planked cousin.

But building in lapstrake is a fine art, and mostly a lost one these days except in a few wooden-boat centers scattered around the country. In the old days the planks had to be finished so finely that they would not leak even in the absence of caulking. These days, a fine bead of polyurethane or polysulphide makes it easier to form a watertight seal along the plank edges but formerly it was the skill of the boatwright alone that kept the water out.

The planking always starts at the keel and works its way upwards. Copper nails with rooves fasten the planks together with a minimum overlap of about 5/8 inch with 1/4-inch planks — and more on bigger boats, of course. At the stem and transom, where the planks come together, the strakes need expert treatment and call for fine woodworking skills.

Older wooden boats without caulking would open cracks along the seams if they dried out for too long, but if they were allowed to soak in water again for a couple of days, the wood would swell and cure that problem.

There isn’t much lapstrake construction around these days, of course, at least not in commercial production, but when fiberglass took over from wood some 60 years or so ago some boatbuilders thought it might be a good idea to produce lapstrake GRP boats.

The problem with that is that fiberglass doesn’t like to make sudden sharp bends, and lapstrake is ALL sharp bends. So they had to fillet the joints between planks into nice gentle curves, which took more material and added weight – and that, in turn, negated one of the main advantages of lapstrake hulls. I expect the construction of a lapstrake mould was also much more difficult and expensive than a plain carvel one. The net result was that a fiberglass lapstrake hull was strong and pretty and more maintenance-free, but often impractical from the point of view of construction and cost.

One-off racing boats are rarely built in lapstrake, despite the weight advantage, because of the added resistance of each lap at slow speeds and because the greater surface area of the hull results in more drag.

One thing that surprises people who have never owned a lapstrake boat is how much noise they make at anchor. Each little passing wavelet smacks into the underside of the laps with great zest, resulting in an unexpectedly loud chorus of noise that owners of lapstrake boats are wont to dismiss as cheerful “chuckles.” But if you’re anchored nearby, in the middle of an otherwise quiet night, you might not be laughing so much.

Today’s Thought
This sort of thing takes a deal of training.
— W. S. Gilbert, Ruddigore

Boaters’ Rules of Thumb #84
Noises in fog. The basic rule is that distant noises in fog sound low and dull. Nearer noises are higher and brighter. Fog carries sound very efficiently so that even faint noises are carried long distances — which makes distance judging very difficult.

Tailpiece
A newly released government report reveals why universities are always referred to as “storehouses of knowledge.”

“It is simply that undergraduates bring so much knowledge in,” says the report, “and graduates take so little out.”

August 15, 2010

Any port in a storm

(The Mainly about Boats column — every Monday, Wednesday, Friday.)

AFTER A LATE POTLUCK SUPPER and plenty of beers on the beach at Shallow Bay, Sam and Dora were invited to Marty and Agatha’s Baba 30 for a nightcap. The anchorage at Sucia Island, one of the loveliest of the San Juans in Washington state, was crowded, as usual, but quiet. A large yellow moon was climbing up behind the fringe of tall Oregon pines.
Marty greeted them from the cockpit, waving a bottle. “Port and cheese to end the evening,” he announced cheerfully, “very civilized.”
“Haven’t tried port,” Sam admitted, helping Dora climb aboard.
“You don’t have a bottle of port aboard?” said Fred incredulously. “I thought every boat carried port. It’s the only wine that improves with travel.”
“Nothing improves with travel on a Catalina 27,” said Dora. “Specially cheese.”
“We’ll have a wine tasting,” Fred announced. “Teach you all about port.”
“Port’s not wine,” said Sam.
“Yes, it is. It’s port wine,” said Agatha, swaying slightly.
“Portifed wine. I’ve heard of that,” said Dora, smiling brightly.
“Not portified, fortified,” Fred insisted. “You’ve heard of fortified wine.”
Dora stared him straight in the eye. “I know what I’ve heard of,” she declared. “You don’t.”
“That's right,” said Sam, “how can you know what my wife’s heard of?”
“Everybody’s heard of fortified,” said Fred. “It’s ten before fiftified.”
Luckily, they all thought that was very funny, not to mention quite clever, and slapped their thighs.
Fred poured large amounts of Warre’s Warrior into glasses and placed a bucket on the floor. Agatha passed around plates of crackers to deaden their palates between sips.
“This is very posh,” said Dora, whose right eyebrow had begun to twitch slightly. “Such a lovely boat, too.”
Fred picked up his glass. “Swirl, sniff, and test the aroma,” he said.
“I thought aroma was the capital of Italy,” said Sam.
“Spaghetti would go quite nicely with this, wouldn’t it?” said Dora.
“No, no it’s an old Perry Como song,” said Agatha.
“What? Spaghetti?”
“No, no, aroma. Arrivederci Aroma, goodbye, goodbye to something ...”
“Concentrate,” said Fred. “Take a small sip, swirl it in your mouth and then spit it in the bucket. What do you taste?”
“Mmmm,” said Agatha. “It’s corpulent, rich and round, with hints of licorice and raspberry.”
Fred held his glass up to the light. “Yes, elegant, no hard edges, the flavor lingers on the palate.”
“It’s like ink,” said Sam. “You ever tasted ink? I sucked some out of a ballpoint pen once.”
“You swallowed your port,” said Agatha accusingly. “You didn’t spit it in the bucket.”
“Can’t help it. Reflex action. I’m a gulper, not a sipper.”
“Well, let’s all gulp then,” said Fred. “And we’ll try again.”
By the time they were halfway through the second bottle, Fred had trouble pouring straight, and Dora’s eyebrow was dancing out of control. Sam complained that his leg was going numb and Agatha could hardly stop giggling.
“Velvety mouth feel,” said Fred, insisting on continuing the lesson, “but it has no lips.”
“What do you mean, lips?” said Dora, smacking hers.
Fred got in quickly. “Lips,” he said, “are to stop your mouth fraying at the edges.” He laughed uproariously at his own joke.
Sam ignored him. “I can do this fancy wine-tasting stuff,” he announced. “This port is elegant. No hard edges.”
“Just like my lips,” said Dora, nuzzling him.
“Concentrate,” said Fred. “When I say it has no lips I mean, well let me put it this way – what flavors can you taste? Quince, raspberry, oak, currants?”
“I thought port was a sailor’s wine,” said Sam. “I think I can taste seaweed, eelgrass, smoked salmon, and mussels.”
“Muscles?” cried Fred, “Muscles don’t have a taste. Muscles is what weightlifters have.”
“Jeez you dummy,” said Sam. “Mussels, not muscles. Shellfish.”
“Shellfish in your wine?” said Dora, holding her stomach. “Like oysters?”
“Okay, okay,” said Fred, “I think you’ve had enough to drink. You’re all blurred around the edges already.”
“I’m sleeping here tonight,” Sam announced suddenly.
“No you’re not,” said Agatha. And she meant it.
For some reason associated with too much port, or perhaps because his leg was still numb, Sam couldn’t start the outboard on their little inflatable, so he got out the oars. The yachts at anchor were black silhouettes against a moonlit bank of white clouds.
Sam stopped rowing a split second before the dinghy crashed into the stern of the yacht. He stood up carefully.
“Jeez,” he said, “somebody stole our boarding ladder. Can you believe ...”
A startled face, pale in the moonlight, appeared in the companionway. It said: “What the hell ...?”
“Burglars!” yelled Sam. “Dora, gimme an oar quick!”
“Shut up you fool,” said Dora. Her eyebrow was twitching nonstop. “Get back down here. And start rowing. We’re two boats over.”

Today’s Thought
To buy very good wine nowadays requires only money. To serve it to your guests is a sign of fatigue.
— William F. Buckley Jr, Harper’s Bazaar, Sep 79

Boaters’ Rules of Thumb #83
Distribution of fog. In U.S. waters, the rule is that the frequency of fog diminishes as you move from north to south — but the change is quicker on the Atlantic Coast than on the Pacific Coast. For example, San Diego and Los Angeles have about three times as much fog as places at the same latitudes on the Atlantic Coast. The foggiest of the foggy places, countrywide, are the coast of Northern California and the coast of Maine, with frequencies of about 20 percent of the year.

Tailpiece
“So did you find a good math tutor?”
“Yeah, he’s so good at math even his teeth have square roots.”

August 12, 2010

Great balls of fire

(The Mainly about Boats column -- every Monday, Wednesday, Friday.)

DOES THE NAME MARVIN CREAMER mean anything to you? It should — because he is one of the greatest small-boat navigators this world has ever known — but it probably doesn’t, because the modest Mr. Creamer, a former professor of geography, has never received the fame he truly deserves.

Creamer is 94 now, and living quietly in North Carolina, but in 1984 he arrived at Cape May, New Jersey, aboard his 36-foot sailboat, Globe Star, after having circumnavigated the world without using any navigational instruments at all. No compass, no sextant, no GPS, no radio — not even a clock or watch.

Just think about that. No compass, for a start. How did he steer across an ocean in cloudy weather? How did he find his way around Cape Horn? The intriguing answers to those and many other questions that are sure to occur to you are in a book that he wrote afterward: a book that, astonishingly, failed to attract a publisher.

It’s available now though, on a self-published CD, for $17 at http://www.globestar.org/

It seems that Creamer had an extraordinary gift for observing certain signs of nature, a gift excelling even the reputed talents of the old South Sea islanders of the Pacific. He knew which birds could fly certain distances from land. He knew the distance limit for a common housefly, too. And he could deduce from the way a piece of wood in a hatch slide squeaked that the atmosphere around him was drier than normal, which meant the wind now had to be blowing toward him from down south in Antarctica.

Direction was everything, of course, the direction of the waves, the direction of the wind, the directions in which land birds flew and transcontinental airplanes flew. After thousands of miles at sea, the landfalls of this extraordinary navigator were rarely more than 15 miles in error.

There was one mystery that he could never answer, though. Down under the tip of Africa one rather hazy night, he and his crew spotted a round light about the size of a grapefruit hovering about 10 or 15 feet away from the side of the steel boat. It was a “clear-cut pale yellow light,” Creamer said, not ephemeral and definitely not a planet.

The puzzle grew greater when they changed tack — and the light stayed in exactly the same position relative to the boat, having moved with it as if it were firmly attached. They never did manage to come up with a theory to explain that phenomenon.

I’ll bet I know what it was, though. I blame St. Elmo, he of the fiery balls. St. Elmo’s fire appears in various forms, one of which is glowing balls that often move along spars or hover high off the deck. It’s actually a luminous plasma originating from a grounded object in an atmospheric electric field.

Wikipedia says (and you have to believe good old Wiki): “The phenomenon sometimes appeared on ships at sea during thunderstorms and was regarded by sailors with religious awe for its glowing ball of light, accounting for the name.” St. Elmo was, of course, the patron saint of sailors.

Today’s Thought
I would rather live in a world where my life is surrounded by mystery than live in a world so small that my mind could comprehend it.
— Harry Emerson Fosdick, Harper 58

Boaters’ Rules of Thumb #82
Action in fog. If you see a fog bank ahead, fix your position immediately, or at least take a bearing. If possible, sail into water too shallow for big ships and anchor there until visibility improves. If you have radar, however, and honestly know how to use it, you can proceed with caution. If you have GPS, you can proceed with even greater caution while blowing your foghorn and idling the engine every five minutes or so while you listen for other signals. Without radar or GPS, proceed with the greatest possible caution while blowing your horn loudly and praying hard.

Tailpiece
The construction department of our local municipality is trying to cross a hen with a concrete mixer.
Apparently they need a more efficient bricklayer.