Is this a Super-Compressor?
Example 1: Baylor Dual-Crown

This watch appears to have all the
characteristics of an EPSA
Super-Compressor: Internal bezel,
fat/chunky crowns located in the
correct locations and a 600 ft depth
rating. It's the correct size for a small
case S-C, and it appears to be the
exact same case as used by JLC
for their Deep Sea Master Mariner
S-C (see below). So far it looks like
a Super-Compressor.
With the case back removed we can
see there is no EPSA dive helmet
trademark or brevet numbers. This
by itself wouldn't necessarily mean
it's not a S-C, as it's possible
unsigned S-C cases were
manufactured.

Compared to the JLC
Super-Compressor in the lower
picture we see the o-ring on the
Baylor is smaller in cross section.
Then look at the inside of the Baylor
case back and you'll see there is no
spring wire assembly, which is
clearly visible inside the JLC case
back.
A close-up of the Baylor case back
shows it is a standard screw-on type
without the Super-Compressor
spring assembly.

Conclusion: This Baylor is not
an EPSA Super-Compressor.

But... EPSA made a lot of cases for
a lot of companies, not all of them
S-Cs. I would estimate this one was
manufactured by EPSA, but without
the S-C "technology".