I believe the issue is that the signal can't travel in water. At least, that was the explanation a few years ago. I doubt the technology is that much better now.
I do believe newer for sake of product differentiation. More and more hardware side of wearable things will use same or almost same internals and differentiation is done by outer casing with software features. That is in generally direction Garmin is heading also. So VA3 is doomed to be fitness wearable without SW driven features for true sport use, I believe. There are other product lines like FR's and Fenix'es that will cover the sport side of things with nearly identical internals but different casing. Even the sensors are mostly the same, if not sub-par barometric sensor selected to VA3 is not taken in account (add elevated clock speed/memory also into the equation from higher end devices).
