10:30pm. Jack and I just came back from our first Bonaire night dive. It coincided with being the first night of this year’s big coral spawning event. Coral sex. How lucky are we.

Coral sex – otherwise known as the broadcast spawn – goes on most powerfully in the Caribbean in September. The corals like to save up their gametes for three to five days after the full moon.

It’s a combination of water temperature and other environmental conditions. It’s the warmest time of the year here. The corals synchronise their times too, so no coral spawns when another coral is ‘busy’. The sperm and eggs float away into one big bundle of culture media. The ocean 😊.

We were to meet Lars and assist in his monitoring work. I’d expected – after getting the email, to see a bunch of divers assembled at 8:30pm. Just me and Jack in the end. And Lars’ friend/colleague.

Lars was already getting things ready. He’d just finished an instructor training dive. And he’d done a cavern dive during the day. And he was about to do six nights of constant night dives. Aha. I was beginning to see why Lars might seem a little grumpy at times. He looked like he might want to install a pillow somewhere into his wet suit.

The plan was to monitor the spawning of the staghorn coral out-planting site. This is the coral that Reef Renewal have planted out into its own reef. Seeing them spawn would be a good marker of the reef’s health and future viability.

We swam from the dive store. In fact, Lars pretty much shot off like a rocket. Luckily, Jack was easier to spot. He’d gone off excitedly during the day to buy a UV torch he’d heard was a good price on the island. He was the one now flashing with different colours. UV, red, spotlight. It was like he was running an underwater disco.

And the disco was for tarpons. Boy oh boy. These huge fish flanked us. As a side job, Lars had given me a bottle and tongs to fill with fireworm. The fireworm predate on the coral. Jack was supposed to shine the torch while I picked them up. Lovely things – they drop their bristles when you touch them. The bristles make your skin itchy and sore.

I found two fireworm. I looked around for the disco man to help me. Where was he? Helping the tarpon to fish by shining his light on the sand! I managed alone in the end. And the coral did spawn – a little. It was a heart-stopping moment to saw little pink balls rise up out of their polyps.

Lars told us after the dive that this was just the warm-up. He’s seen it enough times to know the main spawning night would be the next one. Did we want to come and help again? We nodded a definite yes. A full-blown coral orgy? This time we’re bringing the girls.