Standing at the water's edge in his heavy dive gear, peering into one of the chain of caves which had trapped the Thai schoolboys in 2018, an electrical cable at the feet of Chris Markcrow began to spark and fizz.
The heavy black cables fed power to the pumps set up deep inside the cave system to keep the water level from rising.
The four divers just below him immediately leapt out of the water, fearful a short in the jury-rigged network had turned the whole system "live".
"There was no way of knowing whether it was live or not and the clock was ticking; it was a calculated risk and we had to get in there," the 20-year veteran of the federal police dive team said.
"So my dive buddy and I looked at each other, pulled down our masks and jumped in.
"There were a lot of calculated risks that had to be taken on that job."
Detective Sen Constable Markcrow is one of six Australian Federal Police divers who were awarded bravery medals for their part in the 2018 rescue of the 12 junior footballers who became trapped by rising water inside the Tham Luang cave system, Thailand's fourth largest.
The extraordinary story made headlines around the world and the six Australians were in the thick of it for days - often 14 hours at a time - battling mental and physical fatigue, heat stress, and for a time, wondering if the boys were alive or dead.
The wetsuits and facemasks worn by the divers during the cave rescue form part of an Australian Federal Police exhibition at the Canberra Museum and Art Gallery from now until February next year.
It's a small exhibition but each item has a unique back story which encapsulates the diversity of work by federal officers, from forensics to K9, counter-terrorism to drug investigations, peacekeeping duties and the massive search and recovery effort after the downing of Malaysian Airlines flight MH17, shot down over wartorn Ukraine.
Standing in front of the exhibition of chafed wetsuits worn during the rescue, Senior Constable Mackcrow remembers when the call first came through.
"It was 3.30 on a Friday afternoon and I was on shift down at the water police team sheds at Yarralumla," he said.
"It was the Bangkok office [of the AFP] on the phone asking us if we had the capacity to get over there and, if so, how fast we could do it."
Two hours later he was packing his bags and joining his other team members on the tarmac, piled high with trunks of dive gear, ready for the RAAF flight. At 4.30am the next day, they were on site in northern Thailand.
He described that emergency deployment as the most physically and mentally demanding he has experienced in his 23 years as a police officer and specialist diver.
"The most remarkable moment though was when the confirmation came through to the camp that they [the boys] were alive; the place went dead quiet; everyone knew this was now a time-critical rescue mission," he said.
"From that moment on, every activity went up a gear."