I've been scuba diving for 15 years. I love the calmness of being submerged, the hypnotic sound of my breath and the quiet clicks of fish eating coral.
Last October, I was on a diving holiday in the Philippines with a friend. It was a sunny morning, and after breakfast we boarded the boat with seven other advanced divers. This was my 40th dive, so I knew the drill. I put on the gear and dived off the boat, slowly sinking to about 20m. I saw luminous corals, languorous turtles silhouetted in the deep blue of the ocean and hundreds of tropical fish.
After nearly 45 minutes, the sound of my breathing was drowned out by a low rumble like an engine, and I felt deep, powerful vibrations, as if a big boat with a propeller was passing overhead. I looked up but couldn't see anything. The dive instructor's eyes were wide with confusion: he didn't know what was going on either, even though he'd done thousands of dives. We swam next to each other, staying close to the side of the reef. I couldn't see my friend and the other divers. The situation felt sinister and dangerous.
Then we were enveloped by clouds of white sand that mushroomed up around us, and I thought, could it be an underwater bomb? A giant turtle raced past us and into the deep; they are normally slow movers, so this was very weird behaviour. The vibration became so intense, I could feel it in my bones, and the sound turned into a deafening roar. I could see waterfalls of sand pouring over the coral, and on the sea floor, a few metres below us, cracks began forming and the sand was sucked down. That's when I realised it was an earthquake. The noise was the sound of the Earth splintering open and grinding against itself.
The instructor and I held hands and looked into each other's eyes; I felt comforted by his presence. I was paralysed but clear-headed. My heart was beating strong and fast, and everything seemed incredibly clear and vibrant. I didn't panic, but my body felt on high alert, ready to react. I remember thinking, "I have no power over whatever this is. We are going to have to stay very still and very close, and let it do whatever it's going to do."
The sound and vibrations lasted only two or three minutes, though it felt a lot longer, and when they stopped I heard the swoosh of the sand falling over the seabed. Uneasily, I followed the dive master through the plumes of sand, searching for the others. It took enormous willpower to resist the urge to swim to the surface as fast as I could, but after five minutes we saw them about 20m away and swam over. We all held hands and stopped for three minutes to avoid decompression sickness, which can be fatal. It was a huge relief to see my friend, and we all shared incredulous looks, before finally surfacing, pulling out our breathing apparatus and shouting, "What was that?"
Back on the boat, we rushed to check the news and discovered we had witnessed a huge earthquake, measuring 7.2 on the Richter scale. It released more energy than 30 Hiroshima bombs, and we had been pretty much at the epicentre. I was high on adrenaline and felt lucky not just to have survived, but also to have experienced nature at its most stunning, and most ferocious. On the news, we were horrified to see that more than 200 people had died, with 1,000 injured. I spent the night on the boat with the rest of the group, drinking lots of very strong Philippine rum.
Nearly all those who died were on the island of Bohol, 30 minutes away. That morning, I had been due to take a boat to hospital there, because I had bad earache, but at the last minute I decided to dive. Had I gone, I would have arrived as the earthquake hit. I now believe the open ocean is the safest place you can be during an earthquake: you can move with the tremors, and are far from falling buildings or debris that could kill you. The ocean saved my life.
Two weeks later, when I was back home, I heard that the same area of the Philippines had been hit by the deadliest storm on record, typhoon Haiyan. I was broken-hearted. I contacted the people I'd met and sent provisions and money to the worst-hit areas. The power of that earthquake made me realise how little control we have over life, and how fragile it is. And that it is at its most beautiful under the sea.
• As told to Moya Sarner.