Gorgeous photograph.
I've done submissions to juried exhibits and white/off white mats with black frames are usually the standard for display, and what came to mind is that I think that would work beautifully with this.
I have mats on hand in varying shades of white and ivory (since they aren't all that expensive) and print my own photos (usually glossy which would probably look nice with the water); I need to see which shade mat works with a particular photo. I'd probably go with a plain black frame, maybe a smooth finish rather than textured wood grain since there's so much 'texture' in that water in the photo.
I just find I don't want the mat/frame to detract from the photo but blend and enhance it.