SOGDIVER

And then there is the Blancpain caliber 13P8, which is featured in Caliber Corner's caliber collection.. The 13P8 is a 1315 movement, slightly refined and found on the BP Gombessa Tech FiftyFathom ref...

That being said, there are excellent photos by Hodinkee also featuring good review articles. WatchTime and the WatchPro site also have BP FiftyFathoms/caliber 1315 photos.

Except the open sapphire case back on the FiftyFathoms references, there are precious few 1315 internal views.

The Blancpain 1315 caliber is in many of their FiftyFathoms references. It comes with 3 barrels, 18 K gold rotor, Parachrome-styled mainspring, 5-day power reserve, force-field resistant case, and s...

Some notable brands like Rolex have service interval recommendations. A CW21 watchmaker usually dates and initials the inside of the case back. I wear occasionally a 1960 gilt dialed Rolex Submarine...