Course Corrector of the United States Maritime Commission fixed in original wood box. The divice is a ten inch disk of three rings and has an indicator arm with two thumb screws.

The device is used to assist calculating true, magnetic or compass course base upon variation and deviation.

Catalogue: NM.6-35
Date: 1940 – 1950
HWL case: 4.5x30x30 cm
D corrector: 25.5 cm
Signed: not signed
Origin: USA
Condition: in good and working condition, wear consistent with age and use