Welcome.
That's a spectacular diving shot, but yeah, the lack of water to give it context makes it a little unsettling - as it is, it looks like he's headed for a faceplant into the lane marker roll!
While we're talking about his diving, you certainly look like you've picked the right gear for the job. The K-3ii's lack of an inbuilt flash notwithstanding, it tends not to contribute much at these sorts of distances anyway, except to give the user a false sense of security that "the [usually pop-up] flash fired, so the pics will be be okay" - I learned the hard way in the film era that no, quite often they won't! (And thus began my lust for ever-higher ISO in film, and eventually an SLR when I found to my disgust that my half-frame compact wouldn't take anything faster than 400.)
(Constructive criticism, or rather critique: a slightly higher shutter speed might have elimited the blurs on hands and feet; consider TAv mode, so you can set the aperture wide open, the shutter speed high for motion-freeze effect - especially if you want to capture the splash as he goes in - and the camera will alter ISO for you to maintain the other settings.)