Rolex

Hi, Why do water resistance ratings for the current Sub (300m) and Explorer II (100m) differ? I know the Sub has a Triplock Crown and the Explorer only has a double-lock crown, but is that the only reason for the different ratings? Or is there something e...  

Winding crown ,which I believe has an extra seal fitted. But, if my memory serves me correctly, the Sub & SD used to be advertised in their catalogues as coming with a "Special Case" whatever that meant?? Thicker Stronger??

Only one response? ?? DB Darien

My guess is that ther sapphire may be thicker on the Submariner,, which theorically needs a bigger water resistance. I don't think the case has a different construction. As for the movements, they are basically the same, except that the Explo II has, of c... 

Sub and Explorer 2 has different case backs and crowns. Sub has Triplock crown and thicker case back and these make the WR difference. Cal. 3186 (GMT Master 2) and Cal. 3187 (Explorer 2) are similar. The differences are (AFAIK again) 1. Cal. 3187 has bigg... 

At one point you refer to the GMT II in your post. I assume you meant Sub, correct? And the caliber number of the Sub is 3135, isn't it? But thanks again. DB Darien