# What is this thing on this plane?

**URL:** <https://boards.straightdope.com/t/what-is-this-thing-on-this-plane/411271>\
**Category:** Factual Questions\
**Created:** [July 10, 2007, 10:20pm UTC](https://boards.straightdope.com/t/what-is-this-thing-on-this-plane/411271 "2007-07-10T22:20:14Z")\
**Posts on this page:** 2\
**Page:** 3

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**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\
**Post date:** [July 14, 2007, 7:22am UTC](https://boards.straightdope.com/t/what-is-this-thing-on-this-plane/411271/41 "2007-07-14T07:22:42Z")

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[QUOTE=Testy]  
When I was on ballistic missile boats from '74 to '80, we used LORAN, inertial navigation, GPS, and a few other means of getting our position. Up in a corner of the control room was a wooden box with an **octant** inside. We never used it and most people never knew it was there. The only time it was mentioned was on trick questions during qualifying walk throughs.  
[/QUOTE]  
When I was taking my navigation and pilotage course, we had to learn about plotting courses with a magnetic compass. Even in the '80’s, there was a lot of disbelief that the Powers That Be felt it necessary. Nonetheless, we had to laboriously create a separate heading for each track for magnetic compass readings (taking into account the ship’s magnetic affect on the compass, called the _deviation_). And, of course, even though the ship actually did have an official magnetic compass, it was corrected for the deviation. But by Og, if we were ever required to plot a course using only hand-held magnetic compasses, then we were ready!

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**Author:** ![Testy](https://avatars.discourse-cdn.com/v4/letter/t/c37758/32.png) [@Testy](https://boards.straightdope.com/u/Testy)\
**Post date:** [July 14, 2007, 8:13am UTC](https://boards.straightdope.com/t/what-is-this-thing-on-this-plane/411271/42 "2007-07-14T08:13:43Z")

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[QUOTE=Cerowyn]  
When I was taking my navigation and pilotage course, we had to learn about plotting courses with a magnetic compass. Even in the '80’s, there was a lot of disbelief that the Powers That Be felt it necessary. Nonetheless, we had to laboriously create a separate heading for each track for magnetic compass readings (taking into account the ship’s magnetic affect on the compass, called the _deviation_). And, of course, even though the ship actually did have an official magnetic compass, it was corrected for the deviation. But by Og, if we were ever required to plot a course using only hand-held magnetic compasses, then we were ready!  
[/QUOTE]

I always thought the whole thing was cool in a “Roots” kind of way. I’ll admit that I was never called upon to fiddle with the things or I might have a different attitude.

Testy

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