NavList:

Japanese "Bosun" sextant sounds very familiar, but I can't recall why. Was this an early offering from the little navigation school that later was branded as "Simex"? Clearly this is from the same family of "Tamaya-alikes" with frames and basic functionality manufactured by Tamaya and details (shades, lights, markings) added by various smaller "boutique" companies. Has anyone compiled a list? Bill Morris, do you have a list of these brands? I know of Simex, International Nautical, M.A.C., but there were others. In fact, "Bosun" here could actually be yet another of these boutique brands. These are usually very good sextants, not as good as true Tamaya sextants. I would grade them B+. I currently own an International Nautical and used to have one from M.A.C. These Tamaya-alikes turn up frequently at reasonable prices in the used sextant market, often in near-new condition. I bought one some years ago that had clearly never been removed from the box. There were wrapping materials from the 1970s. It was "new" in terms of use but "old" by manufacture date, and  the grease in the polarizing filters had nearly solidified. 

Frank Reed
ReedNavigation.com
Conanicut Island  USA