THE BLUE WHALE is only a metre or two away from me, and its huge right eyeball is level with mine. I have never seen the largest creature on Earth from this angle, at this depth, in these dimensions. Its body mass fills my vision, and I have to turn my head 180-degrees to take it all in. I’m standing on the bow of a sunken ship, and I have watched, enthralled, as this dweller of the deep sea approached from the dark-blue distance on my left. The surrounding schools of fish and graceful manta rays take little notice of the giant: for them, its presence deserves the equivalent of a submerged shrug; it’s something they see every day. But for myself, standing here on the ship, rooted in place in wonder, it is an extraordinary encounter.

As it hovers before me, the beast blinks and emits a few curious groans before tiring of this underwater interloper. Just another human being. Boring. When it swims to my right in search something more interesting to look at, its tail flukes almost lash me on the way past. In sum, I’ve spent only a minute in its company, but I feel as though quite a few things have changed. This is a fork in the road: my life can now be categorised as ‘Before Whale’ and ‘After Whale’. But perhaps the most astounding part of this experience is that it is running entirely on computer code. Even though every aspect of this scene feels real, it is not.