An interview with Todd Glaser about the July cover of Surfer Magazine, a fisheye shot at Teahupoo of Craig Anderson:
http://www.surfermag.com/blogs/photo-blog/hit-and-run/
In the short interview he explains how Craig Anderson is riding a single fin, not a thruster, and it knocked his dome port underwater, be sure to scroll down to the bottom of the page to see the full sequence.
Going from shooting underwater shots to above water involves changing the focus from very close to the port for underwater to the normal distance, usually a couple of metres away for above water.
I guess he uses back button focusing to achieve this quick enough to capture shots like this when he isn’t expecting it, whichever way he does it it takes some serious presence of mind to get it all right whilst struggling to get under the lip and get the shot and get out of the way of the surfer.
Knowing what he had to do to get the shot makes it even more impressive for anyone like me who is learning surf photography.