The fact is, this watch is not being manufactured to a standard that can guarantee any significant water resistance. I would never trust my life to a device that's assembled with glue, and mass produced in china such that gaskets have been popping out of the digital crowns -- so I would never use it as a dive watch. There's no way to test it, or maintenance it reliably. Apple even says there's no way to test for water resistance after the battery has been replaced, right on their website. Also, many wearers have been subjecting it to aggressive water environments, with mixed results,with the water seals failing over time. This is the natural condition for an IPX8 water resistant watch, the seals have to be regularly serviced, and there's no means to do so with the Watch. Anyone planning on subjecting the watch to excessive water exposure, should invest in a waterproof case, or be prepared for failure. I would recommend Apple Care+ for those opting to throw caution to the wind, and Apple will most likely replace it once.