When one is snorkelling in the open ocean, casually filming dolphins, always keep an eye out for whales....
I was filming a superpod of dolphins off the coast of South Africa, and saw a dusky shark swimming underneath me. I signalled to the other snorkelers there was a shark and heard a shout from the boat "never mind the shark, watch out for the whale!!"
Seconds afterwards, a whale came into view, I think we were both as surprised as each other, and the whale dived to avoid me, accidentally clipping me with its tail. I felt like I had been hit by a bus for several days afterwards as these humpback whales can weigh up to 40 tonnes. A very unexpected experience and one I won't forget for a very long time!