This is a Russian Navy Clock (or Ship's Watch) made for use aboard Soviet submarines during the height of the Cold War by the Chistopol Watch Factory (sometimes called the Vostok Factory).
This factory was founded in 1942 when a Moscow watch-making plant was evacuated from Moscow to a little town, Chistopol (Чи́стополь Now in the Republic of Tatarstan), located on The Kama River.
The company was appointed an official supplier of watches and clocks for the Defence Department of the Soviet Union in 1965. This clock was made in 1966 and has a 12 jewel 8-day movement.
Versions of this clock can often be found on eBay. The ones with Hammer and Sickle on a Soviet star and ones with pictures of submarines are of recent manufacture, and usually have plastic where the glass should be. Real Cold War era versions are more difficult to find and are often not in working condition.
For the life of me I can't understand why this picture is the second most viewed and second most favorited on my stream. Can someone explain?