My last dive:
The blue sapphire sea in front of me suddenly darkened. Nearly 30 metres down in the depths of the Indian Ocean, I knew we were about to come across something big. I just didn’t know what.

As my four fellow divers and I swam closer, the grey, amorphous mass slowly began to take shape and come into focus.

It was the cold glint of a steely eye that gave it away, an eye in such a strange position and on such a oddly-shaped body, it could only be one creature.

Then suddenly, they were upon us: hundreds and hundreds of hammerhead sharks. Above me. Below me. To the side of me. Silhouetted against the sky and as far as the eye could see.