June 20, 2016

Losing control at sea

IT’S A GREAT PITY that human beings are unable to pass on their lifetimes of learning to future generations. Nature has not provided us with the shortcuts she gives to other forms of life, such as birds, which do not have to learn to peck their way out of an egg or how to build a nest. For them, the knowledge is built in. But humans have to learn practically everything over again from scratch, so the accumulated knowledge of people like Einstein is not available to be built on immediately and taken to the next step.   

I mention this because there are always neophyte sailors who are anxious not to kill themselves at sea. This means that as new generations come along they have to learn the same old things all over again.

This is why, every few years, I find people asking me the same old questions, such as “Why do I lose control of the boat when we’re running before the wind in large waves?”

Well, once again let me say that interesting things happen at sea. Your boat loses stability in broken water, for a start. But do you know why boats so often broach, roll broadside on, and capsize when they’re running before the wind in large waves? It’s because when a wave breaks under your stern you have practically no steering power to keep her running straight. The rudder is suspended in foam, not water, and it can’t do its job. If you’ve ever been dumped by a big breaker while body surfing you’ll know the feeling of not being able to float high enough to get your head above water.

And if your boat heels to 45 degrees, you don’t have much steering ability, either. Think about it. The rudder is trying to lift the stern toward the sky as much as it is trying to turn the boat sideways. And, of course, if you do a 90-degree capsize you can’t steer at all. If the rudder isn’t totally out of the water, as it would be on a tubby light-displacement boat, it will be horizontal and unable to turn the stern either way.

Stability at sea is always a fascinating subject for sailors, whether they actually get away from the sight of land or not, and one of the very basic facts about boats is that stability comes as a cube of the length, other things being more or less equal. This means that a 30-footer is 72 percent more stable than a 25-footer, which explains why a 30-footer can stand up to its canvas so much better. It also explains why a 30-footer costs so much more than a 25-footer. But that’s another subject Some other day, perhaps.

Today’s Thought
It hath been an opinion that the French are wiser than they seem, and the Spaniards seem wiser than they are; but howsoever it be between nations, certainly it is so between man and man.
—Bacon, Essays

Golfer: “You must be the worst caddie in the world.”
Caddie: “Oh come now — that would be far too much of a coincidence.”

(Drop by every Monday, Wednesday, Friday for another  Mainly about Boats column.)

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