In a remote corner of Lapland, northern Finland, a group of around 20 scientists and divers have gathered on a frozen lake to train for ice diving. The lake is covered by a 70cm-thick layer of ice, and the water below is just above 0C. The training is preparation for research expeditions in the Arctic and Antarctic, where scientists will study underwater ecosystems and the effects of climate change.
Sophie Kalkowski-Pope, a marine biology graduate from the University of Queensland, is among the trainees. Wearing a dry suit, she braces for the cold shock on her face as she enters the water. Divers can only stay submerged for about 30 minutes before the cold numbs their hands, even with thermal clothing and insulating gloves.
Strict safety protocols are in place. Each diver is tethered to the surface with a safety rope, and a handler communicates via rope signals: one tug for 'ok', two for 'stop', three for 'come back'. A standby diver in full gear is ready to enter the water in an emergency, and two exit holes are cut in the ice. Hazards include entanglement in submerged branches, debris, or the diver's own equipment.
The Arctic is warming four times faster than the global average, and sea ice extent has declined by about 13.2% per decade since 1979. Scientists are learning ice diving to observe Arctic ecosystems and document the ice's retreat. Perry Brandes, a commercial diver from Florida, described his first ice dive as 'very peaceful', with sunlight filtering through holes in the ice like city lights guiding divers back.
The week-long polar research diving course, organised by the University of Helsinki, includes 12 participants who are already experienced divers. Mastering ice diving here could enable them to join scientific expeditions in the polar regions, where additional dangers include large seals that may block dive holes.
