A pair of Spotted Eagle Rays allowed me to join them and swim with them:

I have no real idea how long I swam with them but would guess around 15 minutes or more. The larger one had the lead and the smaller one would either follow behind or abreast. When I first encountered them, they were on the surface in shallow water over the reef and quite active with wings coming out of the water. They mellowed out while I was in their pressence and would swim lazy 8's going away from me and then returning. We ended up in deeper water over the sand and when I left them they again returned to the surface and I could see their wings breaking through the surface when I was too distant to see them under water. I would be more than happy to spend more time watching the flight of these graceful creatures. The visibility was good but the images don't capture the grace and impact of these creatures in motion.