Matt Longbottom and I were waiting out the last two days of a darkwater freedive trip after everyone else had left. We decided to explore a muddy cave close to where we were staying. We were in for a surprise, that was literally groundbreaking.

As a breath hold photographer, I’ve been teaching and filming freediving for over 20 years. I’ve coached six world records, held records myself, run a popular club, taught thousands of people and taken many of them around the world. For the past ten years, I have specialised in extreme location freediving: exploring on a single breath.

There are a few candidates for what I would call the ultimate dive site – mostly in dark water, or underground lakes, where the utter, complete darkness keeps the water impossibly clear. In my opinion, the ultimate darkwater freedive site needs crystal-clear water, technical access possibilities, it should be deep enough but not too deep and should offer stunning vistas below and above the surface.