Season 2 of National Geographic’s worldwide hit series, Drain the Oceans, will feature the most accurate rendering ever made of the Tham Luang cave system in Thailand using advanced mapping and LiDAR technology.
By digitally draining the water from the flooded cave system, the series shows exactly how the group of 12 boys and their soccer coach were trapped, and why it took rescuers three weeks to free them from the extensive underground network in July last year.
Working with authorities in Thailand’s Department of National Parks, Drain the Oceans: Thai Cave Rescue sends a team into Tham Luang to conduct the first digital 3D survey inside the cave. Using a laser scanning system that emits 400,000 beams a second to record reflections from the limestone walls, the team maps the nine chambers that span nearly 2½ kilometres between the cave mouth and where the boys took refuge above the muddy monsoonal flood waters.
Collecting 8.7 billion data points from nearly 400 scans throughout the three-week survey, the team captures every crack and fissure in over 7,000 photos that are pieced together to build a virtual cave and map the boys’ escape route.
By combining this with aerial drone surveys, which show how deep the cave is inside the mountain, it is revealed for the first time how isolated the boys were, and how their efforts to dig their way out left a visible imprint on this underground world.
Once stitched together in a compelling episode directed by Sophie Elwin Harris, the final 3D scan reveals with absolute clarity how the boys were cut off by rising floodwaters in a matter of hours while they explored the caves.
Stripping away the fast-flowing water, which filled several passages, the scans reveal how narrow tunnels hampered rescue efforts; where the guide rope was perilously placed, leading to life-or-death loss of direction; and how much preparation was needed in placing air tanks throughout the caves to move the boys to safety.
Additionally, the episode reveals the risks as rescue divers had to sedate the boys for extraction, not once, but multiple times throughout the dangerous swim to safety after being trapped underground for 18 days.
