But we saw no crocodiles. After two weeks of searching, I was becoming despondent. The deep channel in which we had stopped was clear to its seagrass bottom. I could see over the tops of the mangroves into the meander of the smaller channels. Nothing showed.

The captain, beside me, was becoming agitated. He looked at me questioningly. I sucked my lips inward and sighed deeply. I glanced down at the floor and shook my head. He started the engines and defeat rose in me like a gushing well. As he turned the boat towards the sea, I sagged to its influence, reaching for the rail to support myself. A movement swirled at the side of the boat. Somehow it penetrated the fog of my despair. I looked again.

‘Croc!’ I shouted. ‘Croc, croc, croc.’

I grabbed the captain’s arm, pointing wildly at the water beside us. He cut the engines. We drifted tense into the wash of silence, all eyes on the water. The crocodile surfaced ten metres (thirty feet) away, in the shallows of the channel’s bank.

I don’t remember descending the steep stairs. I scrambled for my fins and camera gear, telling Beverly in a hissed whisper to keep eyes on the crocodile. From the transom of the boat, I lowered my legs into the water, checked my camera settings and reached for the mask that the divemaster held out to me. He pulled it away. I looked, frantic in my haste, towards him. He wagged his finger at me.

‘Slowly, slowly,’ he said. ‘Very slowly.’