The Black Sea is littered with deadly weapons. But no one knows how many – or where they are. When we approach it, we should be quiet, we should be slow – and we should be very accurate, says Vitalii, a 31-year-old Ukrainian Navy diver, describing the meticulous process of swimming through dark waters toward explosive devices resting on the sea floor.

Vitalii is part of a team of 20 tasked with de-mining areas of the Black Sea under Ukraine's control. Mines are among the most insidious and long-lasting legacies of war, remaining active and deadly for decades, particularly as sea mines can drift with currents and storms.

The sea mines laid by Moscow at the beginning of the full-scale invasion pose immediate dangers; last summer, three swimmers were killed by mines off the coast of Odesa.

According to the navy's mine countermeasures group commander, known as Fox, thousands of mines are scattered across the Black Sea, yet they are not the only hazards. Unexploded missiles, artillery shells, and bombs have also washed into the sea due to the destruction caused by the Kakhovka dam explosion in 2022.

Despite the scale of the contamination, maritime traffic has not halted, and numerous merchant ships continue to operate within the only maritime export corridor out of Ukraine. Operational safety is contingent upon clearing the seabed of these threats, underscoring the divers' vital role.

Through painstakingly slow movements and specialized equipment, divers like Vitalii move carefully toward each object. Once identified, the detonating process often takes place the next day, preceded by strategic explosions to disable the mine's sensors. This procedure involves multiple boats and up to 20 personnel, all under the looming threat of aerial and underwater attacks.

We find new ways to strike them; they look for ways to counter us. What works today will not work tomorrow, Navy spokesman Dmytro Pletenchuk explains, emphasizing the cleverly dynamic nature of naval warfare.

Even as dangers persist, the revenue from maritime exports remains crucial for Ukraine's economy amid ongoing conflict. The challenges facing the diving teams are formidable, and without a ceasefire, they project that it could take decades to fully clear the seabed of explosives. Until then, divers like Vitalii will continue their dangerous work, moving through the water one careful second at a time.