‘Cool,’ Andrew says, ‘so the worst is over?’

‘Not exactly,’ Vanessa sighs. ‘Global warming won’t magically improve. And pollution is still a big problem,’ she says, ‘fertiliser from the nearby banana farms is really harming the reef.’ Vanessa gazes at the horizon. I nod vigorously. Vanessa is saying exactly what Millie thinks! I glance at Hugh. He’s pointedly staring at Vanessa. He’s not smiling.

Andrew looks sombre.

‘Garbage is also a big problem,’ Vanessa continues. She inclines her head towards the ocean. ‘Almost every dive I go on, I find plastic.’

‘So, the coral bleaching could come back?’ pipes up Natalie, surprising me, and by the looks of it, Hugh as well, with her interest on the subject.

Vanessa sighs and nods. ‘Every year we roll the dice on whether it will get worse,’ she says.

Natalie sits back in her seat, her expression blank. She whispers something to Derek, who nods. I wonder what she’s thinking. I glance at Hugh and he makes eye contact with me, raising his eyebrows triumphantly before settling back into the bench.

Any hope I had that to look for the butterfly wrasse in peace disappears. He knows I’m searching in hopes it will divert some fund-raising efforts towards pollution, and he thinks I’m not going to find it.

I want to ask Hugh if we can just agree to disagree, and not talk about it, so I wander to the front of the deck, hoping he will follow. There’s a platform on the hull of the boat that’s raised (it’s right over the portion that’s below deck), and it’s large enough to fit two or three people. I climb on top of it and sit myself up against the window to the crew’s room to stretch my feet out. The sun is bright, and I’m thankful I put on a large T-shirt before lunch. There’s a zero per cent chance I can make it through these few days without getting sunburn.

There’s a hammock right next to me that stretches from the window to the mast for the large sail, but I don’t want to be the person who claims the hammock immediately when it’s clearly the best seat in the house, so I stay put.

I gaze out across the ocean and take a deep lungful of salty air. The morning fog has completely lifted. White boats speckle the horizon, all of them appearing after we surfaced from our dive. They’re still far enough away that they’re just dots, and Aaron said they probably won’t come any closer.

‘So, what did you think of our first dive?’ Miguel asks me excitedly, interrupting my train of thought. He’s paused in front of me, mid-walk to the front of the boat.

‘I loved it.’

He bobs his head in agreement. ‘What’s not to love?’