When US and Israeli forces launched strikes on Iran on 28 February, triggering one of the most serious geopolitical crises in years, the Strait of Hormuz - a narrow channel just 34 kilometres wide at its narrowest point - became a global flashpoint overnight.
Iran closed the waterway to foreign shipping, attacking merchant vessels and cutting off around 20 per cent of the world's seaborne oil trade. Some 20,000 seafarers were stranded in the Persian Gulf. The UN Secretary-General called for an immediate ceasefire.
Beneath all of it, the fish kept swimming.
Back in the water
Three Chinese divers based in the United Arab Emirates (UAE) - diving instructor Rui Li, freediver Shanshan Du and technical diver Jie Zhang - had been locked out of the water for weeks by the coastal closure. When a ceasefire allowed limited access in mid-April, they went straight back in.
World Oceans Day , marked each year on 8 June, carries the theme this year of Reimagining the Relationship Between Humans and the Ocean. For these three, that reimagining is anything but abstract.
"We were actually a little worried before setting off," says Du, who dived the narrowest stretch between the UAE and Oman on 18 April, just days after the UN welcomed Iran's announcement that the strait would be open to commercial vessels during the ceasefire.
"But after more than two months, we all felt it was fantastic to be able to dive again. We encountered a large group of dolphins. There was none of the war-torn atmosphere I had imagined - only peace and beauty before my eyes."
Zhang, who dived the area as recently as last week, describes coral diversity she has rarely encountered elsewhere - soft and hard corals varying with the topography, and sea turtles gathered in such numbers they evoked a nature reserve.
Troubling signs
She also noticed something more troubling. "I saw more white debris on the seabed than before," she says, uncertain of its origin. And when she and her companions followed dolphins near the eastern side of the strait, the water around the animals was streaked with green algae, oil fumes and floating rubbish.
"I recalled that when I used to chase dolphins, the water was blue. Seeing this scene with my own eyes is still very heartbreaking."
Li is careful to hold both realities at once. The strait is not the world's most biodiverse marine zone, he notes, but its complex topography sustains coral reefs of unusual variety - formations "as white as silver needles" alongside colonies "as purple as pine forests" - as well as seahorses, whale sharks and species rarely seen elsewhere.
He describes witnessing a boat captain who, unable to dive and with no other means of communication, could reliably find a pod of dolphins that seemed to recognise him. "We would greet each other and then go our separate ways," Li says. "This place is truly magical."
Potential catastrophe
Yet he is also acutely aware of what armed conflict can do to such a place. An attack on oil storage facilities, he points out, could be catastrophic for marine life. "Many marine organisms are small and vulnerable. A single attack could be enough to wipe out some amazing species that have never been seen by humans."
Zhang frames the underwater world's vulnerability in blunt terms. "No one can speak for the underwater ecosystem - fish can't speak, and neither can large animals.
"We dump all the disputes, wars and pollution on land onto the ocean, ignoring the fact that the ocean has no good self-protection capabilities and can only bear all the conflicts and damage caused by human activities."
Diving has quietly dissolved certain certainties for all three. "Underwater, the ocean has no borders," says Zhang. "Ocean currents and schools of fish move freely. When whale sharks cruise, they follow fixed routes through different countries - they are free. Humanity should share this blue world instead of tearing it apart with disputes."
Mother ocean
Li reaches for a different metaphor - warmer, and perhaps more honest about the limits of human agency. The relationship between people and the sea, he suggests, is something like that between a child and a parent: the ocean sustains us, nurtures us, occasionally punishes us.
"We have grown old enough to want to protect it, he says, yet what we can actually do remains small. "Our parents are still quietly waiting for us, helping us, and continuing to nurture us."
Du, diving in a country where people of dozens of nationalities converge, has found that underwater, borders feel beside the point. Communication happens through gesture alone. "Because of this hobby, and because of the ocean, it has created a wonderful environment for us."
The conflicts raging above the surface have not ended. Talks between Washington and Tehran remain fragile, conditions volatile. But 71 per cent of the Earth is ocean - and, as Li says to anyone who has yet to see it: come and touch the refreshing water whenever you can.
