Found two sources of info, hence both a bit different:
https://www.gearpatrol.com/watches/a40082973/omega-seamaster/
https://www.omegaseamaster300.com/
What is for sure is, that the Seamaster 300 was just a model name.
I wonder if it could pass the test with the naiad system crown, as the screw down crown was added later to fulfill the MoD requirements.
I have 2 watchco builds, one Naiad and one screw down crown, but both were tested just to 100m.
But me thinks the sdc version would pass the 300m wr test without any problem.
From my understanding, the problem with the naid crown was not at high pressures, but at lower pressures near the surface. It worked assuming an external pressure pushing it in to make a tight seal. That worked fine at the 200m pressure test, but often failed when swimming!
hence the switch to a screw down. It was production, I think introduced in 1967 or 1968. My 1966 reference had a naid crown and I never took it near the water!
Riddle me this: What year was the Niad crown introduced on the Seamaster 300? And if the screw down crown update wasn't made until 1967 or 1968, how many years was the Niad crown installed on the 300?
What I'm getting at here is how could the 300 go so many years in production with a faulty crown before being fixed?
@Archer , do you by chance have any test results and/or insight on pressure test capabilities?
Thanks Archer. Do you know what year the screw down crown was phased in on the Seamaster 300?
Did Omega ever offer an antimagnetic movement dust cover for the Seamaster 300?
From my understanding, the problem with the naid crown was not at high pressures, but at lower pressures near the surface. It worked assuming an external pressure pushing it in to make a tight seal. That worked fine at the 200m pressure test, but often failed when swimming!
hence the switch to a screw down. It was production, I think introduced in 1967 or 1968. My 1966 reference had a naid crown and I never took it near the water!
Here's what's interesting about the "300" being just a model name theory: The Seamaster 120 was rated to 120 meters per the vintage ads!
The Seamaster 300 as pictured with the earlier Niad crown was rated a 200 meters. So why didn't Omega call the 300 instead the Seamaster 200?
Does anyone know when the screw down crown was first fitted on the 300? Was it during the production run? Or was it a service bulletin update that occurred after the watch was discontinued? Has anyone tried pressure testing the Niad and SCD at 300 meters?
