# Watch: Why The Zig-Zag Search And Rescue Pattern is Genius

Interesting video, CG small boat search techniques explained and with an actual drill on the water.

Watch: Why The Zig-Zag Search And Rescue Pattern is Genius

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That was a great episode. I really enjoy this guyâ€™s stuff.

The boat crew is using a device similar to a nautical slide rule to calculate the course to use for each leg (itâ€™s at about 11:10 in the video. Hereâ€™s a screen shot:

The center part shows the legs to be run and can be rotated like a nautical slide rule to find the true course to be steered (outer ring).

The narrator calls it a â€śnomogramâ€ť but based on a quick skim of Wikipedia that doesnâ€™t appear to be the correct term.

According to Wikipedia a nomogram is:

a graphical calculating device, a two-dimensional diagram designed to allow the approximate graphical computation of a mathematical function.

Thereâ€™s one on the DMA radar plotting sheet for calculating speed / time / distance.

The navigator uses dividers or a straight edge to solve r * t = d. Paper charts also had a similar one.

Donâ€™t know if there is a specific term for the device used in the video but based on the Wikipedia definition itâ€™s a â€śsimple analog computerâ€ť.
From Wikipedia:

Analog computers can have a very wide range of complexity. Slide rules and nomograms are the simplest, while naval gunfire control computers and large hybrid digital/analog computers were among the most complicated