I know some people were really tired of my issues with getting the Garmin fenix 3 watch, but I have to say that it's been awesome.
Oh, and also, the fenix 3 is rated to 10 atmospheres which means roughly 100 meters, or about 328 feet deep. It's plenty 'waterproof', but they do discourage deep water scuba diving, and high velocity water sports.
The idea that something isn't completely waterproof isn't all that hard to understand, at least for me. I've been very reluctant to push any buttons when the fenix is wet, because pushing buttons could allow moisture to get inside. My TAGHeuer watch was good to 300 feet, but you would have to be insane to think that you could loosen the crown and adjust the time at any depth.
And wearing an Apple Watch that I had paid nearly $1,000 for swimming wouldn't be something I would ever want to do. Unless I was really rich, really stupid, or both. Plus it made me wonder since Apple seemed to be hedging in the beginning on the idea of 'water resistance'...
I friend of a guy I used to dive with 'flooded' his Nikonos V dive camera. It seems that he didn't like having his camera serviced, and was on a dive trip to the Caribbean, and Murphy chose his first day to flood the camera due to an o-ring failure. It was a 'live aboard' trip, and he would have forfeit the balance of the trip, and dumped his wife and friends there while he shlepped around to find some place to fix it, so he stowed it, and took it to the local big city dive shop to get it serviced. It had started rusting at that point, and the film was ruined, and it was a mess... His insurance didn't cover it for some reason. So 'waterproof' is more, and less, of what it is... AND your mileage may vary.