Kristina at Dos Ojos

The beautiful caverns of Dos Ojos were the setting for my favourite and most ground-breaking shoot to date.

Kristina and I first heard about Dos Ojos in the resort pool on our second day in Mexico. It was unknown to most of the Quintana Roo tourists, with barely any mention of it at our hotel. Just as well: its majesty would not be quite so apparent if it were crammed with people.

Hidden under the jungle canopy at the end of a long, dusty road, Dos Ojos is a flooded cave system that still has not been fully explored. It is one of the planet's longest and most impressive underwater cave systems, made up of 28 cenotes across 51 miles. Derived from the Mayan word dzonot, meaning sacred well, a cenote is a natural limestone sinkhole giving way to pristine groundwater. Dos Ojos refers to two of the larger caves, the two eyes, believed to look into the underworld.

As an experienced scuba diver, I had not seen water so beautiful since diving off the coast of Fiji. We peered into the darkness of the caves, watching bats dodge stalactites, and knew we had struck gold. We settled at the second eye and watched swimmers and divers disappear into the tunnels, their torch beams revealing patches the filtered sunlight could not reach.

I encased my camera in its new Outex underwater housing and waded in. We set off exploring one of the nearby branches and found the setting sun bathing a stretch of rock in stunning light. The crystal clear water shimmered in blues and greens, illuminating submerged stalactites below. We soon realised we were in a race against the sun.

We had practised only once before, in an open air cenote a few days earlier, which is testament to Kristina's talent. We wanted to create a majestic vision of her diving underwater, among the fish, rocks and stalactites. With the sun setting and the water temperature dropping, our challenges mounted. She began to tire, I got colder, the ISO climbed, but the pictures stacked up.

Much too soon the Caribbean sun had set. The cave was dark and deserted, and we pulled ourselves from the chilling water. It is a shame we did not have more time, but it only makes me prouder of what we managed in six or so dives. The other caves will have to wait.

We learnt so many lessons from this, and not just how to swim, model and photograph underwater, which turns out to be much harder than anticipated. I learnt that this is the kind of work I want to be making: the kind that pushes boundaries, shows lesser known parts of the world in new ways, makes you look twice, and is hard.