Navigating the Tsunami: A Submarine's Survival Below a Catastrophic Wave

Imagine a situation so apocalyptic that a submarine could successfully dive below a tsunami. This is not science fiction, as I can vouch for from personal experience. What follows is an account of a terrifying yet survival tale from the Maldives, where we were enveloped in the aftermath of the 2004 Indian Ocean Tsunami.

In the Eye of the Storm: Our Experience

In 2004, I was working at a beautiful resort called Filitheyo in the North Nilandhoo atoll, and I had the privilege of diving with a couple of French tourists, a father and son pair. Most of our introductory dives are conducted in the pool, but we preferred to introduce them to the rich marine life as soon as possible. That day, our confined water dive began at about two meters, but something unusual caught our attention.

The current started getting stronger, an anomaly given the sheltered nature of the lagoon. I didn't realize then that we were caught in the midst of a tsunami's confined water phase. As we continued with our exercises, the current suddenly turned in different directions, and the water level began to drop. I instructed the students to return to the beach, which turned out to be wise, as we witnessed the water rising above the reef and then draining below it, an eerie yet familiar cycle.

Understanding Tsunamis

Contrary to popular belief, the massive waves seen in Thailand were not caused by the tsunami itself but by the contour of the ocean floor. The tsunami travels over deep waters where it is barely perceptible. As it approaches shallower areas, the immense amount of energy is released, creating the destructive waves that we associate with tsunamis.

In the Maldives, the situation was different due to the geology and location. These atolls are essentially the summits of underwater mountains, rising vertically from the ocean floor over 3000 meters to the surface. The tsunami hit these walls, producing minimal wave action but an overwhelming current. Additionally, Sri Lanka’s location played a significant role in absorbing most of the energy.

The Underwater Apocalypse

Meanwhile, my colleagues diving near the north of the island experienced a strong current pushing them towards the inside of the atoll. The water level was rising, filling the atoll like a bucket. As the bucket reached full capacity, the water began flowing out in the opposite direction, creating a powerful downward drift.

The underwater scene was chaotic. The current surged above 60 meters, capable of dragging divers and their clients towards the abyss. Sand from the atoll's floor was stirred, making it impossible to read dive computers or locate dive buddies. The pressure on their eardrums increased as they were dragged downwards. Reef boulders, larger than child bicycles, rolled down the underwater escarpment creating a thundering noise.

Everyone, including the instructors, inflated their BCDs. Swimming against the current was impossible. They were forced to ascend towards the surface, a fait accompli. No one ended up in the decompression chamber that day due to the reasons mentioned above: half a day of diving and the use of nitrox 32, a mix with a higher oxygen concentration.

A Personal Perspective and Legacy

One of my colleagues, a Maldivian dive master with 5000 dives under his belt, was so terrified that he cried uncontrollably for an hour. We couldn’t stop him. When they returned to the island, we were all glued to the news, the death toll doubling every hour. In the Maldives, approximately 80 deaths occurred, mostly indigenous people who had never learned to swim. It’s remarkable how such a fundamental survival skill was deemed less important on this remote island.

The aftermath was a scene of devastation, with sea planes washed up on jetties and a pilot having to abort takeoff due to fishes flapping on the runway. That was the indelible memory of the 2004 tsunami for me, and I realize now how fortunate we were to navigate through such a terrifying ordeal.