Sorry for jumping in late but as suggested by others above, this is either a Jenkins Whipray (H. jenkinsii) or a Tahitian Ray (H. fai). I took lots of shots of these at Ellaihdoo, Maldives in April and researched the precise i.d. when I got home (they were just called "Whiprays" out there). I doubt anybody can tell them apart in the field but the chances are it is the Jenkins variety as, although both occur in the Indian Ocean, Jenkins is much more common here. I believe the reverse is true in the Pacific.
Just to confuse things further, Jenkins is often called the Pointed-nose Stingray - and is so called on Fishbase which is the world wide authority on fish nomenclature.