Water resistance with crown unscrewed?

[Tools]

One thing to note on the "Crushed Oyster" test is that it is an Explorer case, even though it is a Sub advertisement.

So, even with the Twinlock crown and thinner case, no seals gave out until the case was completely crushed..

[Dirt]

Originally Posted by Abdullah71601

If your argument were true, the case would breath whenever you changed altitude. Air travel would be disastrous to your watch.

The structure of the case minimizes deformation under the great pressures (10 Bar and up) at depth. The case doesn't change shape much (as a percent of total volume) above it's crush depth. What little deformation there is compresses the air only very slightly. The air inside isn't at all a factor in water resistance.

The water resistance is entirely the seals pressing against the metal surfaces. The case can deform substantially before the seals lose enough integrity with the surface to leak.

Thinking about it, you're quite right.
Any pressure increase on the inside would be insignificant compared to the outside pressure and would contribute very little(if anything) useful toward withholding water ingress past the Crown seals

[Abdullah71601]

Originally Posted by Dirt

Thinking about it, you're quite right.
Any pressure increase on the inside would be insignificant compared to the outside pressure and would contribute very little(if anything) useful toward withholding water ingress past the Crown seals

[Dirt]

Originally Posted by Tools

One thing to note on the "Crushed Oyster" test is that it is an Explorer case, even though it is a Sub advertisement.

So, even with the Twinlock crown and thinner case, no seals gave out until the case was completely crushed..

Yes, in essence the advertisement was really about the integrity of the design of the Rolex Twinlock Crown seal.