The situation on June 27 was this: a large and growing rescue operation existed at the cave entrance. No one had been able to get past Sam Yaek. No one knew whether the team was alive. The rains were continuing. The water was still rising.
—
## Calling in the Specialists
The critical intervention that changed the technical capacity of the rescue came from Vern Unsworth, a British caver and cave diving enthusiast who had spent years exploring the Tham Luang system and knew its geography better than almost anyone.
Unsworth recognized immediately that the Thai Navy divers, however skilled in military diving, did not have the specific skill set that penetrating a flooded cave system of Tham Luang’s complexity required. Cave diving is a highly specialized discipline distinct from military or recreational diving. It involves navigating through completely flooded passages with no surface and no ambient light, following a guideline laid in advance, managing buoyancy in confined spaces, and dealing with the specific problems of zero-visibility water in tight tunnels — all while carrying enough breathing gas for the passage in both directions. The number of people in the world who can do this at the level required for a rescue operation in a system as complex as Tham Luang could be counted in the dozens.
Unsworth pressed the Thai authorities to contact the British Cave Rescue Council. The BCRC mobilized on June 26, dispatching Rick Stanton and John Volanthen as the first specialist divers. Stanton was a retired firefighter from the UK who had been cave diving for decades and was considered one of the most experienced cave divers in the world. Volanthen was an IT consultant with comparable experience and multiple cave diving records to his name.