Cosmic mantas

It's amazing, but manta rays have such an aura! When you dive with them, you can totally feel their presence. And I don't just mean the huge shadow they cast (with a wingspan of up to four metres).

The last time, at Koh Bon, west of Thailand, we were just swimming about underwater, minding our own business and generally looking at the coral, when suddenly this silence seemed to descend on the reef and its little inhabitants. And then, these two mantas slid gracefully into view. I was transfixed. Wow!