Blue sea, blue sky, mirroring each other. The sea is oily, but this is just a pretence of calm. Less than an hour ago, we leapt off Pokohinu – Burgess island – in heaving swells, waves thrashing the boulders, the bay a washing machine fed by swells pounding through the channel between the narrow island and the stacks. I’d been the one securing our field gear in the dinghy as we disembarked the island. To ferry gear we string the dinghy on long ropes between boat and shore, shuttling full loads to the boat and empty ones back. With the wave action, it was impossible to pass things down and secure them, so it was left to me to leap in as it rode the swells up to the rocks, and then catch our various bags, boxes and fish bins as they were dropped from above. I’d barely landed in the fretfully bobbing boat and I was soaked. Waves bounced off the rock shelf and broke over me in a froth of white, salt in the eyes, trying not to get smacked in the head by a dangling pelican case. Grab, untie, stow, next. Until with a small but secure load, I was pulled out to the relatively calmer waters in the middle of the bay to pass gear up and into our ride home. And then back again, into the fray. At least I’d been too busy and chilled to feel seasick.

Now offshore, the long swells stand in a row of hills behind us, speeding us home. Warm winter sun washes over me, replacing salty cold shivers. The Mokohinau islands rise and fall, rise and fall and vanish, swallowed by the sea. Diving petrels erupt from the glassy water, making off on rapid wingbeats, or splashing below to wing away submerged. They’re sharp in fresh plumage, monochrome with striking blue feet. Back from their migration to the Antarctic convergence, where they moult. Such a tiny bird to go so far, on stubby wings, over the ocean. They don’t think about it, they just do it. Much like leaping into an inflatable in heaving swells – don’t think, just do.