Aircraft Bubble Sextant, Japanese Imperial Navy (SEXT41)

This is a WWII-era aeronautical sextant used in aircraft of the Japanese Imperial Navy, as evidenced by the anchor symbol stamped on the data plate.

According to collector George Fulford's notes:

This astonishing find seems to be the only one in existence. I’ve researched extensively and there is zero reference to it in any source. Up to the time this was made Japan military used a good copy of the obsolete USAAF A-8, of which I have Japanese and American samples in this collection. What is impressive about this particular bubble sextant is how sophisticated it is. You can see the original RAF features plus what the Germans also adapted to create their own masterpiece. Clearly, the Germans had some – if not all the design – input in its design.

The name Sokkisha has great significance to the mystery, as they were know to be famous for their high quality surveying instruments, but before WW2 and especially so to day. Checking out their web site and also writing to them added nothing to solving the mystery, but there is no doubt they made it as the Japanese characters explicitly say so. My guess is that all the records were destroyed in WW2.

I have some very significant sextants in this collection, but this is probably one that will have every collector’s head swimming with curiosity.