January 4, 2015

Judging your speed through water

"A LONG TIME AGO you wrote about orange peel as a method of judging a boat's speed," says a message from Lora, of Carlsbad, California. "I made a note of it -- but lost it, of course. Could you please repeat it?"


Sure thing, Lora. Here it is again. Print it out and pin it to your . . . well, something you won't lose this time:



MY FAVORITE distance log was one of those old Walker taffrail logs with the trailing line, the propeller, and the whirring dials. It served me well for thousands of ocean miles. It had only two enemies: seaweed that jammed the propeller and sharks that swallowed the propeller.
In later years, I got my distance run from a tiny GPS that cost less than half the price of a Walker.



It was magic, but it wasn't the same. I missed the ritual of reading the log and streaming it. It took me most of a week to figure out how to bring in that spinning propeller without creating a bird’s nest of twisted line, but in the end I got great satisfaction from doing it right. Somehow, just pressing a button with my thumb doesn’t provide the same pleasure.



However, you don't really need a Walker log or a GPS to find out how many miles you've traveled in a given time. All you need is the number of hours you've been sailing, and (duh) the speed of travel.



You can get the number of hours from a watch, of course, and you can learn to estimate speed surprisingly accurately, but there is a better way than just estimating. You need nothing but a piece of orange peel and a small timer/calculator.



Multiply the length of your boat, from bow to stern in feet, by 0.59. Note the figure, and keep it handy for future reference. Now throw a piece of orange peel forward of the boat. Start timing when the bow comes abreast of the orange peel.



Now note the time it takes in seconds to reach the stern. Divide the first number by the second to find your speed in knots. If you don't have a good timer, you can simply count the seconds, using the old trick: "one Mississippi, two Mississippi," etc. You'll find it's plenty accurate enough for the speeds at which small sailboats travel.


(Oh, and by the way Lora, you don't have to use orange peel. A piece of crumpled paper or a banana peel will do just as well.)



Today's Thought
Four hoarse blasts of a ship's whistle still raise the hair on my neck and set my feet to tapping. 
  --John Steinbeck.



Tailpiece An odd-job man called at a friend’s house the other day.
My friend said, “OK, how much to paint the porch?”
“Fifty dollars,” said the man.
"Done,” said my friend. “Here’s a brush and a bucket of paint.”
Half an hour later the man knocked on the door.
“Finished,” he said.
“Wow, that didn’t take you long,” said my friend.
“Nah, it wasn’t very big,” said the man. “And by the way, it’s not a Porsche, it’s a Mercedes."


1 comment:

Charles Reynolds said...

I have been staring at, and drooling for, a Knotstick for quite some time, now. This is a trailing knot meter similar to the old Walker log; and inexpensive, too!