Antique Octant's

Welcome to our selection of antique octants. The antique octant is a very desirable maritime instrument, they are also a symbol of seafarers who have navigated the worlds oceans by using only the sun and stars for fixing their position. The primary use of a navigation octant is to determine the angle between an astronomical object and the horizon for the purposes of celestial navigation. The angle and time can be used to calculate a position line on a nautical chart. Common uses of the octtant include sighting the sun at solar noon to determine latitude.

Below is our selection of antique navigation octants


A fine early 19th century navigators Octant made by Steele & Co, Liverpool with applied makers plate.

Ebony frame with brass fittings, double-hole sighting pinnula with swing cover. Pencil compartment with press on cap.

The scale is clearly engraved -2 degrees to 106 degrees and is divided into 10 minute increments.

Index arm length 10" / 30 cm, radius 9.5" / 24 cm.

Complete in original Oak stepped keystone box.

The scale is also engraved SBR (Spencer Browning & Rust) near the 50 degree mark, this indicates that this Octant was probably made by Spencer Browning & Rust who produced navigation instruments from 1784 to 1840 and Steele & Co Liverpool were probably the retailer. 

Original Oak stepped keystone box. 

Antique octant shown with box.

Reverse side of the antique octant.


A mid 19th century navigators Octant.

Unsigned brass 'T' frame design, trade label inside box for D. Mc GREGOR & Co, LIVERPOOL.

The scale is engraved from -5 degrees to 125 degrees and reading to 100 degrees. The index arm has swinging scale magnifier, the vernier scale reads from 0 to 10 seconds of arc.

Complete with two sighting telescopes, telescope sun filter and mirror adjusting pin, contained within its original mahogany box. Height: 9.75 inches / 25 cm, Radius: 7.5 inches / 19cm.

Close up of antique octant ivory scale. 

Exterior of the hardwood octant carrying case / storage box.

Front side of the antique octant with telescopes, eye piece filter and accessories.  

Reverse side of the antique octant.