Two enormous fish cruise past you. What to do? They make reef fish look like entirely different animals. You call over to your diving group through your regulator. ‘Guys!!’ They’re all busy staring at a rock.

Surprise at seeing these goliaths at the concrete pier was an understatement. But I wasn’t scared. Ha! This is progress.

I noticed it when we night-dived a couple of nights ago. We all took turns putting our dive gear on. I got into the water first. Bobbed around in the darkness while everyone else got ready. I have to admit – the last time we did our night dive, Lu got into the water first. The fifteen-year old.

This time, I felt my body calm in the darkness – even more calm than normal. And when the fish came past me at the edge of the pier’s metal forest, still bathed in sunlight, it was the same. My breathing slowed.

The fish were easy to recognise. They were tarpon. Known as the silver king, tarpon are the only species of the family Megalopidae. There are two types; Atlantic and Pacific tarpon, though there is possible inter-breeding. Tarpon are thought to slip through the Panama Canal and ‘meet’ their oceanic cousins.

Megalops – the Latin name for tarpon, means ‘great face’. Great face indeed. They aren’t considered eating fish, being too bony, but are prized gamefish for the fight they put up. I stared at their huge inquisitive eyes. Scales so bright, they could have been recently polished. They seemed to be as curious of me and I was of them.

The concrete pier is a dive where the light plays with you. Full of huge, sunken tyres in which reef fish have made ecosystems. Jack played with an octopus sheltering in a round metal basin.

At the beginning of the dive, we found a seahorse. I saw it clinging to a metal box. It was Pascal from s/v Felicity who told me to look out for them. This seahorse was the biggest I’ve ever seen. As orange as the waving sponge next to it.

Jack uncurled it from the box and we watched it swim off freely – until it crashed sideways into a piece of coral. Urghh. Do seahorse have bad balance? Luckily, it didn’t seem hurt. It righted itself and swam off again.

We made our way through the pier legs. The tarpon returned. Three of these giants swam past us and turned around. Apparently tarpon will find an area they like and school together for years. They are unique too for having a lung of sorts, evolving their swim bladder which functions normally for buoyancy, to breathe with. They also come to the surface and gulp air.

We hung in the water. The tarpon repeated the routine, swimming through the metal trees and returning back to us. Each time they got closer. The last time they approached, I waved. Could have kissed them. Their eyes widened. Then they swam off again.