@andres @Tom Henriksen
A crown unscrewed makes no difference to water resistance? Hard to imagine that the pressures at 100 meters would not overcome an [effectively] opened case.
Wouldn't this reduce the seals to "single-lock" status with no crown o-ring being squeezed by the screwed down crown?
People dwell too much on the "Twinlock/Triplock" thing.. and believe that this is what makes the watch waterproof.. There are many watches waterproof to this depth without a screwdown crown..
The o-rings inside the tube are very robust, provide most of the seal protection, and it takes a lot of pressure to push water past them. Proof is in the o-rings on the pushers on the Daytona... It too is waterproof to 100 meters and there is no screw down crown on them, only the small o-ring on the pusher stem...
For the first years of it's existence, the Sub used a Twinlock crown.