Waterproofing
Waterproof Daytona
[Source: Rolex Forums]
The Rolex Cosmograph Daytona, with screw down pushers, is waterproof to the same 100m capability of all Oyster Cased Rolexes. The Daytona is waterproof whether the pusher screwlocks are tight or not.
The pushers internal actuation are the weak link for this depth rating and must not be pushed while submerged. To ensure this, screw locks are fitted to each pusher.
The pusher is an assembly that contains it’s own internal “O” rings and is screwed into the case with a gasket seal against the case. When the pusher is depressed, it deforms the “O” rings slightly and may allow water to enter the movement through the actuator rod hole. They also may be inadvertantly depressed so the usual mode should be with the pushers screwed down and locked unless in use.
Daytona Info 