It's not a watch. Under US Regulations, it can only be called "Water Resistant" if it is a WATCH and list the depth it is rated for. So they are not selling it as a time-piece. Any clam of "waterproof" is hype.
See http://www.rolex.com/watches/datejust-ii/m116300-0007.html
Rolex pretty clearly states that the watch is waterproof. There is also paperwork that comes with the watch stating as such.
It is rated IP68, the highest rating for waterproof.