Description
The Astra IIIB is the perfect Sextant for beginners, yet some several professional navigators prefer the Astra IIIB. Lightweight aluminium frame which will resist corrosion, and reduce fatigue and unsteadiness among infrequent users. Electrically lighted by a LED on the arc and drum, making it so easy to use, and being lightweight it is a pleasure to hold, making sights easier to take under dynamic weather and sea conditions. Reading the sextant is easy under low light, the Astra has white degree marks against the black background as opposed to scribe marks on a brass arc. The Astra index mirror is rectangular in shape and is the same as used what is used on more expensive sextants, the shape allows more aspect of the mirror to be available for high angle sight, meaning the sextant does not have to be held as steady. Each mirror and shade glass is tested for perfect flatness by the Fresnel diffraction pattern method. Sextants are assembled and tested n a clean professional environment, random units have been tested by several professional navigators.
- Comes in a varnished wooden case
- LED lighting arc and drum powered by 2 x AA batteries (not included)>
- Arc -5 degree + 130 degree, radius 153mm
- Micrometer drum 1' scale, vernier to 0.01'>
- Horizon mirror 51mm
- Index mirror 56 x 42mm
- Shade 4 index - 3 horizon
- Certificate of accuracy
- Adjusting wrench
- Case diameter 6.5 x 13 x 11 inches
- 3.5 x 40" monocular telescope as standard equipment
- Weight 2lbs, 10 ounces