It’s colder with the sun down, and I start to shiver when I strap on my BCD. Hugh sits down next to me, and I crave his heat but he looks preoccupied and I don’t want to disturb him, so I resist the urge to scoot closer. When we do the buddy checks, he avoids looking in my eyes. I purposefully take longer than necessary to pressure test the straps and check his air pressure, trying to meet his gaze to reassure him that everything will be fine, but his eyes are glued to the floor of the boat. It’s only when I start to visibly shiver that he breaks his silence.

‘You’re cold,’ he says, placing a hand on top of mine. The gesture is jarringly intimate. The warmth from his hand feels divine. I feel myself relax towards him, like I’m slowly melting in his direction.

‘And you’re nervous?’ I whisper, venturing a guess as to why he seems so withdrawn into a shell.

Almost imperceptibly, Hugh nods.

I squeeze his hands. ‘It’ll be great,’ I say, both to myself and to him.

He squeezes mine back and attempts to smile, but it doesn’t reach his eyes.

Miguel and Vanessa hustle us into the water.

We descend into pitch-black. It’s hard to believe this is where we were diving just two hours ago. In the darkness, it’s impossible to see anything. The water feels warmer than the cool night air. I remember learning that water gains and loses heat much more slowly than land. The resurgence of knowledge I thought was lost momentarily lifts my confidence, and I descend lower, finding my buoyancy, hovering three feet off the ground, waiting for Vanessa to give direction.

With flashlights, we can see pretty well. We’re hovered over white sand, and I spot a sea cucumber in my peripherals. We’re momentarily stalled waiting for Andrew to equalise and find his buoyancy. I look at Hugh to see if he’s laughing, but I can’t see his face in the darkness. I try to remember what Hugh explained about our flashlights, how Aaron and Pippa will be looking after us from the boat, but the pitch-dark is all-consuming. I sift through facts in my brain, seeing if I can remember anything from Principles of Oceanography, my favourite class freshman year, the one that set me up to get a degree in marine biology. If I can focus on facts, maybe I’ll be less spooked by how much of my surroundings I can’t see.