1974 Tissot Visodate Seastar ref. T12 44518. Compressor 42.2 x 50mm. case, bi directional internal bezel, movement cal. 784-2, the case back features the classic sailing ship logo, a fitting trademark of the Navigator line.
The Super Compressor watch case was patented in 1956 and manufactured by Ervin Piquerez SA (EPSA) for almost two decades. Most of the Super Compressors can be identified by their twin crowns and internal rotating timing ring.
The name actually referred to the cases sealing technology, which made use of a spring-loaded case-back that sealed tighter as external water pressure increased. EPSA’s logo was a stylized diving helmet and could be found either on the outside or inside of the case-back. The crowns are typically cross-hatched, oversized and thick, making it easier to operate them under water.
Over 100 different brands used one of the many variations of SC cases. Some notable brands used the dual crown design, including: Jaeger leCoultre, Longines, Universal Geneve, IWC and Blancpain.
Tissot was founded in 1853 in Switzerland offering the first mass-produced pocket watch in that year. They went on to introduce a number of firsts: first anti-magnetic watch, first watch made of stone, wood and plastic.
Interestingly, Tissot merged with Omega back in 1930. Lemania, the movement maker joined the group 2 years later and became the chronograph movement maker for the brands. Having a captive chronograph maker enabled both Omega and Tissot to become official timing partners for many events such as the Olympics, Formula 1 and other sporting events. Tissot and Omega used a lot of similar or even same movements over the years. At times, Omega used a slightly more advanced version or one with more decoration – think of it like VW and Audi. Omega, Longines and Lemania have been under the Swatch Group since 1983.