‘It isn’t far. We should be there soon.’

He manages a weak smile, then drops his head once David steers the boat around and motors us out to sea. The thrum of the engines vibrates through my body, filling my ears with its drone until I can barely hear the gulls and the relentless wind is reduced to a thin whistle.

While Tom hunkers into himself, I turn my face upward and breathe in the salty air. The water is brisker away from the land, the choppy green-grey waves churning and heaving, their colours darkening to murkier greens and black. Staring into their depths fills me with melancholy and I pull my gaze away and watch the trails of white bubbling in our wake. As the shoreline dwindles, I’m gripped by the sense that my life will never be the same again. That somehow, I can never go back.

The boat picks up speed, waves hitting us on every side and sending spray exploding over the deck. Glancing at Tom, I wonder whether to tell him about the things my mum said and everything that’s been happening. He grips the seat, his knuckles white, and then bends forward and covers his mouth. Maybe now isn’t the time.

A shadow falls over us and I look up and see a bird, flying three or four metres above the boat. It’s almost impossibly big – a prehistoric-looking thing that reminds me of a Pterodactyl. Several more appear alongside it and a shiver of excitement runs through me. I hold up my arm and my heart lifts, wishing I could reach out and touch them, wishing I could fly with them. The feeling surprises me and I laugh at myself. I’m like one of the little kids at the butterfly centre, enraptured by the magic of nature.

David shouts from the cab. ‘Tom, isn’t it? Come and look at this!’

Tom groans, his face sickly pale. I can’t see him going anywhere until we’re back on dry land. Watching my footing on the slippery deck, I walk over and he mutters, ‘Gonna vom’, then turns and deposits his lunch into the sea.

I pat his back, wishing I could help. ‘Hang in there.’

He wipes his mouth and looks so embarrassed I feel bad for him. I reach inside my bag and hand him a bottle of water.

‘You know what’s good for seasickness?’ I ask.

He takes the water and smiles weakly. ‘Sitting under a tree?’

I laugh. ‘Keeping your eyes on the horizon, it can help to re—’

He shoves me aside and I jump back as he vomits into the waves again. If there’s one thing worse than throwing your guts up, it’s doing it with an audience.

Deciding to see what David wants, I lift up my shorts and head to the covered cab. The relentless rocking of the waves is worse now I’m standing, and it isn’t long until sweat prickles on the back of my neck and I start to feel queasy. I walk a few steps and the boat lists to one side. Taking a deep breath, I get my balance and shuffle forward when it moves in the opposite direction, making me lurch sideways.