Boat Plans Uk | Navigation is not precise

Boat Plans Uk

ONE OF THE THINGS that small-boat navigation teaches you is that nothing is precise. The best navigators make allowances for the unknown factors that always affect small boats, especially sailboats. They plot their positions within a circle of uncertainty and if they’re seeking landfall at a particular spot on a coastline, they aim way off to one side or the other, so they know which way to turn when they sight land.

When I was a lot younger I thought I knew how to navigate with precision. This misconception was confirmed when I sailed a 17-foot dinghy across the English Channel from Dover to Calais. I studied the tide tables and figured out the speed and direction of the tidal stream (or the set and drift as I used to call it then) for every hour. I then drew my course on the chart and adjusted the compass heading to account for the distance the tide was pushing me sideways in each hour. And thus, with a great sense of triumph, I arrived off the rather featureless French coast exactly at Calais.

It was beginner’s luck, of course. Nobody can forecast the exact speed of the current, or its exact direction. Nobody can tell you how much leeway your boat will make. Nobody can forecast your exact speed or distance covered during any one-hour period, and so the detailed markings you make so carefully on the chart turn out to be nonsense. In my case, it was probably a matter of all the errors canceling each other out — a minor miracle in other words.

Years later, when further experience had taught me some humility, I read The Yacht Navigator’s Handbook, by Norman Dahl. In the introduction he says: “When I was first taught navigation (in the Royal Navy) errors were thought of as being rather disgraceful, the sole result of poor technique by the navigator. Whilst I always accepted (and still accept today) that I was not the most brilliant navigator in the world, I was disappointed to find that, however hard I tried, errors never seemed to go away. Navigating a submerged submarine, and later, yachts of many kinds in many situations, eventually made me realize that errors are an integral part of navigation and need to be studied in their own right.”

Dahl said a major purpose of his book was to show that errors in navigation are normal and natural, and that a major skill in navigation lies in your ability to interpret the results in terms of the likely errors. He goes on to show boat navigators how they can actually use the errors to help make sensible decisions about their positions and a future course of action.

As one who had never experienced any difficulty in making errors I found Dahl’s advice very comforting, and I never again tried to do anything as impossibly precise as maintaining a rhumb line from Dover to Calais.

I expect Dahl’s book is out of print now because it was first published in 1983, before the great revolution in navigating that finally did bring near- precision to position-finding. We don’t think of errors now, because GPS doesn’t allow for that. It will tell us our position to within a boatlength in any kind of visibility, day or night.

And yet people have run aground using GPS, often because GPS is more accurate than the charts you plot your position on. There have been many reports of yachts wrecked on rocks, reefs, and islands that were where the GPS said they weren’t.

So we now all find ourselves in the position that I was in all those years ago, when I knew precisely and without doubt how to cross the English Channel. It’s surely time we started doubting again. It’s time we listened to Mr. Dahl, time we started taking all the possible errors into account. Time to accept that navigation is never precise, even with GPS.
Happy New Year
I wish you all health and happiness for the coming year. May 2016 also bring you prosperity in all meanings of the word.

Today’s Thought

The greatest of faults, I should say, is to be conscious of none.

— Carlyle, Heroes and Hero-Worship: The Hero as Prophet

Tailpiece

“What made you marry old Bella?”
“She was different from all the other girls I’ve met.”

“In what way?”
"She liked me."

Do you find information about Boat Plans Uk are you looking for? If not, below may help you find more information about the Boat Plans Uk. Thank you for visiting, have a great day.

Read More..

Boat Plans Australia | The joy of small simple boats

Boat Plans Australia

SAILING, FOR MANY GOOD REASONS, tends to be regarded by the general public as a complicated and expensive pastime. But it needn’t be. Small simple boats can afford pleasure and gratification out of all proportion to their cost. And small gentle voyages can generate as much joy and satisfaction as long adventurous ones.

The man or woman who gingerly sails a dinghy along a friendly shore is no less worthy of our respect than the sailor who braves the mighty ocean. 

We all have our own areas of anxiety and doubt in our own abilities, and when we conquer our fears it is just as much a triumph to cross the bay as it is for someone of sterner nature to cross an ocean.

And yet, human nature being what it is, we tend to judge other sailors by the size of their boats and how far they’ve traveled: their most distant ports, and the length of their voyages.

Now it is true that sailors who cross oceans in small boats perform prodigious feats of seamanship because they sail the same seas as big ships that have large crews specializing in the various skills needed to move people and cargoes across oceans. Sailboat sailors are their own cooks and navigators. They are their own engineers and riggers. They handle the sails and anchors and electrical circuits. And they face exactly the same hazards as large ships, including the storms, the rocks, and even pirates.

Yet, at the same time, to take a small boat across a body of water of any size is no small feat. To each his own goals and ambitions. We all set our own limits, and who can gainsay our individual achievements? What we all seek deep down is a feeling of ability, of achievement, of confidence. And sailing a small boat on a small voyage often does generate the confidence we need to deal with the greater troubles the world constantly throws at us.

Seamanship is as much a set of the mind as anything else. You are the only judge of your seamanship. We challenge ourselves, we feel fear, and sometimes we get more fear than we bargained for, but we learn and we gain confidence, and are not as frightened quite as much the next time. And there always is a next time for those who challenge themselves.

Today’s Thought

Keep your fears to yourself, but share your courage.

— R. L. Stevenson
Tailpiece

Mary had a little lamb

That leaped around in hops

It hopped into the road one day

And ended up as chops.

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

Do you find information about Boat Plans Australia are you looking for? If not, below may help you find more information about the Boat Plans Australia. Thank you for visiting, have a great day.

Read More..

Boat Plans For A Chesapeake Deadrise | The most wonderful mystery

Boat Plans For A Chesapeake Deadrise

A READER in Newport Beach, California, says she would like to know what the Bible means when it says:

 "There be three things which are too wonderful for me, yea, four which I know not:
"The way of an eagle in the air; the way of a serpent upon a rock; the way of a ship in the midst of the sea; and the way of a man with a maid."

Specifically, “Nautigal” wants to know about the way of a ship in the midst of the sea.

Well, ma’am, science has made great progress since those words were written. We can explain an eagle’s flight with aerodynamics. Herpetologists now know how a snake slithers across a rock. Dr. Phil understands all too well the wicked way of a man with a maid (and spares us no details). And that leaves the ship in the midst of the sea, the most wonderful of all the mysteries.

Little ships, and especially little sailing ships, conduct themselves in many different ways in the waves of the sea. You may have experienced them all without giving any particular motion a name or a definition. But one man made a list for us to wonder at.

He is the well-known American naval architect and author, Francis S. Kinney. He held that there were eight motions of a sailboat at sea:

Broaching: Accidentally swinging broadside on to the wind and sea when running free.

Heaving: Rising and falling as a whole with the seas.

Pitching: Plunging and scending, so that the bow and stern rise and fall alternately.

Pitchpoling: Accidentally tumbling stern-over-bow in a half-forward somersault.

Rolling: Inclining rhythmically from side to side.

Surging: Being accelerated and decelerated by overtaking swells.

Swaying: Moving bodily sideways.

Yawing: Lurching and changing direction to either side of a proper course.

I note that the discreet Mr. Kinney refrained from mentioning wallowing and foundering, which has happened in boats I’ve sailed. The foundering was in a small sailing dinghy, luckily, and there was a sandbank nearby. Perhaps Mr. Kinney’s designs never did those things. But he might well have included heeling, which is simply deliberately arrested rolling.

So next time you’re out there, “Nautigal,” take note of what your boat is doing, and at all costs avoid pitchpoling. That’s the most dangerous motion of all.

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, “The Mystery of Life,” in Riverside Sermons

Tailpiece
A man rushed into the dining car of a train. “A lady just fainted next door,” he cried. “Anyone got any whiskey?”

Several flasks were offered. He grabbed the nearest one and drained it in one gulp.

“Thanks a lot,” he said, “it always upsets me to see a lady faint.”

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

Do you find information about Boat Plans For A Chesapeake Deadrise are you looking for? If not, below may help you find more information about the Boat Plans For A Chesapeake Deadrise. Thank you for visiting, have a great day.

Read More..