|
Knots
to You
From Our Chapter’s Safety officer, Dick Sligh |
| The
days before GPS, speedmeters and loran, a boats' speed had to be determined
for proper navigation. This was done by a "Log". The "Log" consists of a chip log and line. The line was wound up on a reel. The chip was shaped like a piece of pie or 1/4 circle. The line was attached to the "pointy" end. The circular edge was weighted so the chip would float upright when it was dragged behind the ship. he line has a series of knots spaced 47 feet - 3 inches apart. The chip is thrown into the water from a moving ship. The "Knots" passing off the reel are counted for 28 seconds. The speed of the ship is determined in "Knots". For math freaks, the reason this works is; a nautical mile is 6,076.1 feet. So, 28 seconds are to one hour as 47 feet - 3 inches are to 6,076.1 feet. One nautical mile on the ocean surface amounts to one minute of angle at the equator, 60 nautical miles to a degree, 360 degrees to the circumference of the Earth. Finally, do not say knots per hour. "Knots" indicated distance over a period of time. It is right to say miles per hour but not to say knots per hour. Now that you know where "Knots" came from, go out and buy a hand held GPS for $150.00. Otherwise, just go out boating, have fun and know that our ancestors had a lot more fun trying to figure out where they were and where they were going. |