I was extremely lucky to have this encounter with this beautiful dolphin (total of three) :). Sea was perfect, not the best light; dolphins where so near I had to change my 70-200 and use the 17-40. Enjoy.
I like the splash as they are cresting the surface. Getting them both in the same position was part good luck and part being ready for it.
Would have like to see a bit more room near the fins but you got enough room up front and that is the important part. If this is cropped somewhat I would add back some of the room in the back and balance that with a bit more room up front.
Another vote for a little more space around the left fin. I really like how the cresting splash is shooting into the same direction as the subjects, adds to teh sense of motion. I also like the color/texture of the water.