‘Well, luckily I’m not a doctor, so saving you is not in my job description at all. I’ll alert the dive centre to come and get you . . . eventually,’ I said, relishing our role reversal. ‘Okay? Bye.’

I was about to pull on my goggles and stroke back to shore when I noticed his leg. Or, rather, the absence thereof. His left leg was amputated from the knee down. Attached to his stump was an Oscar Pistorius–type blade.

When he noticed that I’d noticed, his dark eyes glittered but he said nothing. I didn’t know what to say, so I dog-paddled in awkward silence for a moment.

There was no way I could leave now, despite how annoying I found the man.

I quickly calculated the distance to shore. It was only about one kilometre. ‘Can you swim? I mean, with your . . .’ I still hadn’t quite worked out how to mention it, and the bastard doc chose not to make it easier. ‘I suggest we just ditch the board and freestyle in together.’

‘You seem to be forgetting my whole shark phobia,’ he admitted, glancing apprehensively down into the depths.

‘Most creatures are scared of humans. We hurt sharks far more often than they hurt us.’ I’d been around Emerald for long enough to know that. I hauled the top half of my body up onto the board, on the same side as the doctor. ‘Let’s kick the board in to shore,’ I said, and started a frantic cancan in the water.

The doctor tried his best, but his right leg was much better at displacing water than the blade, so the board began moving in a circular direction.

I checked our position against the headland. It was then I realised we were in a rip – a current that was dragging us out of the inlet towards the open ocean.

‘Look, why don’t I swim to shore and raise the alarm? You just lie on the board and wait. Okay?’

I shoved on my goggles and slid back into the water. I was freestyling fast towards the shore, diagonally, to cut across the rip, when my eyes focused on the sandy-ribbed bottom of the sea. It looked like pale corduroy. But it also seemed to be moving oddly. At first I thought it was just reflective ripples made by the rogue tide. But with a sickening thud of my heart, I realised that the sand was alive with sea snakes.

I turned around and snorkelled at breakneck speed back to the broken windsurfer. My legs were kicking so frantically, I must have looked like the horizontal, aquatic version of Riverdance.