This vintage Breitling (1965) has a really interesting chronograph function. The large hand with the square on the end is not a seconds hand, in fact it is a minute counter hand. When the chronograph is activated, it moves slowly, one minute at a time, and there is no seconds register.
Also, because it is not apparently obvious that the chronograph is working without a seconds hand, the aperture above 6 o’clock fills in with a black disc when activated. If this isn’t a cool and interesting chronograph, we don’t know what is.
Not too many of these SuperOcean ref. 2005 survived until today, even less with all-original movements, the non-screwdown crown led to a lot of humidity damage and quite a bit of rusty movements
The movement used in the ref. 2005 is actually a well known one, the Venus 188 chronograph movement, but heavily modified by Breitling, it measured elapsed diving time in minutes (the rhomboid-tipped hand), a display at 6 is blank when the diving timer is inactive, shows a big green lume dot when engaged, a small lume dot when paused.
Great example of a very early dive watch