Pentax's WR?? submersion in saltwater

I have no experience with Pentax or it's WR range, but as mentioned above the WR stands for "Weather Resistant", not water resistant or waterproof. The Pentax website actually mentions "it’s weather-resistant to handle damp, inclement conditions."There is a BIG difference between "damp" conditions and submersion

In Canon L series lens and camera body terms weather resistant means different things, especially with the bodies, but it NEVER means waterproof. A Canon 6D body is described as weatherproof and so is a Canon 1DX, but the 6D might handle a few minutes of light drizzle, whereas the 1DX might handle a wave splash. Some L series lenses are described as weather resistant against dust or dampness ingress (I have a few L lenses and have never more anything more definitive than this on Canon's literature), and some of them require a filter to be fitted to the front element to achieve this.

There has been many discussions in the Canon forums about the WR and the reports vary significantly with some indicating survival of a short fresh water submersion (on a pro-level body and L series lens), whereas others report water damage (terminal or requiring a Canon repair) after being caught in a shower of rain, so there is no definitive standard.

Worth noting that Canon doesn't actually state that any of them are warranted against water damage.

So, unless Pentax has done something dramatically different to Canon, the WR just means that the gear is likely to survive a light drizzle of rain, but not much more. On ILC systems the WR means something completely different generally to what WR means on a small compact camera.

Colin