Join Date: Jun 2005
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"Stupid human trick"--estimate bearings without yr compass
So, here's a "stupid Human trick"--estimating degrees of angle w/o instruments
Did you ever want to be able to easily determine approximately how many compass degrees something is from something else?
there's a simple way, no equipment needed (even though yes, you do have a compass I hope).
On average, a fist (with thumb on top, not wrapped around the fingers), on an arm fully extended in front of your eyes, describes an arc of ten degrees, from bottom of pinky finger to top of thumb.
So--is boat A two fists off your headstay? that's 20 degrees. Try doing this with nine fists in succession and you'll see you've made a right angle (90 degrees), whether you are moving horizontally for a terrestrial object, or vertically for a celestial one.
And you can be a latitude-navigator without a sextant. Find the North Star (Big Dipper outer two stars of the spoon point you towards Polaris). Either see (twilight) or estimate your horizontal horizon, and go fist-over fists up to Polaris. Four fists? You're at 40 degrees latitude (Massachusetts!). 3 Fists? New Orleans (I know this one, 30 degrees north of the equator). Latitude navigators discovered the world centuries before they figured out how to find longitude.
How long til sunset (Moonset)? Easy. How many fists from sun down to horizon, or vice-versa? 4 and a half fists? that's 45 degrees. The sun (and all sky objects) "move" at 15 degrees an hour (since Earth rotates 360 of them in 24 hours, si?). So you have 3 hours to finish that dive, or that round of golf. Each fist is worth 10 degrees, so that's 40 minutes of movement. So, if you want cut it closer, each finger/knuckle is worth about 2 degrees, or 8 minutes.
And, a fist is almost 11-1/4 degrees, which is a "Point" forus sailors and historians ("Land ho, 3 points off the port bow!!" a point being 360 degrees divided by 32, if you've ever "boxed" the compass). Now you know what they're talking about in "Moby Dick" and such.
So the human trick ain't so stupid, eh? (hey, trust me, I'm an English Major)
Last edited by nolatom; 08-07-2013 at 12:35 PM.