Kriegsmarine slide rule from the Kiel Naval School.

Very good condition with KM marking on the box and the slide rule.

On the front of the box: Albert Nestler AG, D.R.P. "Kiel" 20/3. On the back: Property of the Kiel Naval School and eagle. On the slide rule inside: a. o. eagle and property of the Naval School Kiel No. 6485. Mint.

Dimensions with box: approx. 30 cm

These slide rules were also used in submarine training. It can be used to calculate e.g. the angle of lead and the fuel consumption. Of course, it was also used in navigation. According to an entry on Rechenschieber.org, they are still popular on submarines today because you can sometimes get the result faster than electronically.