Why I Love … scuba diving

I remember looking through a diving mask for the first time. I'd just read Jacques Cousteau's Silent World, I was nine years old, standing waist deep in the River Devon, a small tributary of the river Forth in Scotland. Peering down at the minnows darting around my toes, I knew I was hooked.

The world under the sea still fascinates me. Whether the colourful riot of a coral reef, the pollock glinting behind waving kelp fronds off the Irish west coast, the Gothic gloom and almost eeriness under the ice, a dive can be everything from a weightless space walk to a powerful physical challenge as you feel the strength of the surf moving you around. It helps to be fit but to my mind being underwater doesn’t involve competing with the elements, it’s about going with the flow, feeling at home in the sea.

I've been everywhere, from the west of Ireland to the Red Sea and the Canadian Arctic. My most memorable moments underwater have been in the company of other marine mammals, particularly the big guys, the whales. That's when I choose what I call my "seaweed" approach; adopting a mindset of almost indifference as I slip quietly into the water from the boat. No jumping – that's likely to spook them. Slow languid fin strokes, ready to stop just as soon as I can make out their shape. Gently, I keep my distance, they have to get to know me first. Relax, let the whales sense me as harmless as a piece of seaweed, yet also as an object of curiosity.

Give them time, they’ll accept my presence, they will come close. It’s their choice, and that’s what makes a close encounter with another mammal in the sea such a privilege. Their approach is a reflection of my behaviour, if I play it right, this whale will befriend me, and I really can claim to have had relationship with an alien. What could be more satisfying than that?