Davis Mark II Plastic Marine Sextant

The octant has a grey plastic plate, a plastic handle and a stiffening bar on the back. It has one blue plastic index shade and no tangent or clamping screw. Index and horizon-glass adjustment is made by screws with an Allen key. Attached to the octant is a plastic, non-adjustable telescope bracket. The fixed plastic sight-tube is 32 mm in length with three plastic shades in blue, yellow, and green. Accompanying the octant is an Allen key. The octant has no box.

The instrument has a grey plastic scale from -35° to 100° by 1°, measuring from -14° to 100°. The octant has a plastic vernier measuring to 2 arcminutes, with zero at the left.

This instrument has been identified as an octant, because it measures up to 105 degrees. The iventor, however, identified the object as a sextant.

Object Details

ID: NAV1186
Collection: Astronomical and navigational instruments
Type: Octant
Display location: Not on display
Creator: Young, Douglas Johnson
Date made: 1965
Credit: National Maritime Museum, Greenwich, London
Measurements: Overall: 73 mm x 213 mm x 217 mm