That water is insanely clear man! Great shots. If I were you on the second cut (after the zoom transition). I wouldn't slow the video down so much, I personally don't think it needs it. But if you know you wanna do it. Maybe shoot 1080 60fps or higher. So it's not choppy when slowed down!
I'm pretty amateur with my edits myself so I don't know what value my opinion holds haha. Take it as that!