Ben Oostdam story # 15


In 1961, we still used the three point sextant fix for accurate bathymetric surveys. The three points are landmarks A, B and Cfor example, a lighthouse, a stack and a prominent tree. One sextant operator, say Fran Shepard, shoots the horizontal angle A-B, the other (e.g.I myself), simultaneously shoots angle B-C. The angles are recorded (say, by Elizabeth Shepard) and plotted using a 3 arm protractor (since that time, made available in plastic thanks to Japanese ingenuity).

Below, some NOAA archive photos to illustrate:
Three-Arm Protractor Use to lay out course lines or plot fixes from multiple fixed positions obtained by a sextant or hand bearing compass. Translucent to allow overlay on a chart with full visiblity underneath. Center arm is fixed with two adjustable arms and a hole in the center of the compass rose for marking your position. Fully flexible and nearly unbreakable. Arm length is 15" (38 cm) - DAVIS

I noticed that Elizabeth acknowledged every reading we called in by intercom (one a minute each) by climbing up on the counter, turning the switch and shouting "AYE AYE", after which she would climb down and record the time and angle.
BLO fecit 20021001 adj.20060605

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Since she was over 60, I thought this was too much, and I taped a string to the switch on the intercom. I told her all she had to do is to pull the string and shout "AYE AYE", so no more need for climbing. Also, that Fran would never find out...