Garmin loves to endlessly differentiate their products, and I'm a little surprised they haven't done more with their scuba platform already. But I could totally see Garmin creating a cheaper recreational type scuba watch that's a simpler version of the Descent. The dive computer market has a lot of stratification, and Garmin is only competing in the premium portion today. They could potentially offer something cheaper without all of the tech and CCR stuff.
My only question is what kind of fitness platform would they use as the foundation? Is scuba a higher price option for existing platforms (the Forerunner or Venu with scuba) or will it be its own platform (a simplified Descent focused on diving)? Will it have other fitness capabilities at all or just do diving stuff?
The scuba market is pretty small relative to the broader fitness market, so I suspect Garmin would look to cheaply retrofit the single tank dive capabilities onto an existing down-market fitness line rather than create something new from scratch. No idea which line though, and no idea about the branding either.