With the support of the XDEEP Exploration Support Program, Bottomline Projects embarked on an ambitious cave-diving expedition in Thailand’s Satun region, a remote area rich with unexplored underwater cave systems. The team faced technical challenges, logistical hurdles, and unexpected discoveries as they pushed the boundaries of known cave exploration. The expedition spanned multiple caves, each presenting its own set of mysteries and obstacles.

One of the most exciting aspects of the journey was the team's dive into Toh Wang Cave in Payabangsa Mountain, previously explored by the team last year to a length of 1400 meters. As the team, equipped with sidemount dive gear configurations centered on the STEALTH 2.0 buoyancy system from XDEEP, descended into the unknown depths, they split into specialized groups. Some were focused on detailed surveys (Mika Lindström and Pasi Laihanen). In contrast, others (Maxime Cheminade, Polphut Bualoi, and Anand Sekaran) worked on the comprehensive 3D map of the cave. The third team, composed of seasoned cave explorers (Mikko Paasi and Naomi Allen), ventured further than any diver had before. Armed with sidemount rebreathers and underwater scooters, they pushed past the known endpoint of the cave and extended the exploration line by an additional 350 meters. This was no small feat, as navigating narrow, water-filled passages at a max depth of 30 meters required immense concentration, precise technique, and constant vigilance for diving equipment or environmental challenges.

While Toh Wang Cave proved both intricate and vast, the team sought new frontiers. After a strategic meeting with local National Park officers, the Bottomline Projects crew shifted their focus to an uncharted location, initially explored by Folk Sassadee up to 500 meters, where a siphon had previously halted exploration. Determined to push beyond this obstacle, the team plunged into the water, only to find that the sump—a seemingly impassable section—was actually a mere 15-meter watery pond. On the other side, the cave opened into vast new chambers, ready for further exploration. Although the dive team didn’t push further this time, their discovery paved the way for local surveyors to continue exploring this previously unreachable cave section.

The wonders of this newly accessed cave were more than just geological. As the divers explored further, they stumbled upon a startling historical discovery—prehistoric human remains estimated to be around 10,000 years old. These remains were nestled in a chamber adorned with intricate stalactites and stalagmites, creating a surreal connection between the cave's ancient human visitors and modern-day explorers.

In a race against time, the team split into two groups for their next adventure. One group of CCR divers returned to Toh Wang Cave at Payabangsa Mountain to continue extending its passages. Their efforts were rewarded with an additional 100 meters of newly laid line, bringing the cave’s total length to an impressive 1850 meters. The magnitude of the cave system was staggering, as the journey to the end of the exploration line and back now required three hours of underwater travel, aided by scooters and advanced rebreather systems. Simultaneously, another group of OC divers ventured into Pakwang Cave, a system previously thought to be much smaller. By the end of their dive, the team had extended the cave’s passage by 100 meters, discovering new passages and pushing the maximum depth to 30 meters. The team also noted multiple unexplored offshoots that hinted at more discoveries waiting to be made in future expeditions.

Toh Wang Cave offered its challenges, with its cavern section requiring careful surveying. Por Parasu Komaradat and his team tackled this portion of the expedition, conducting a meticulous survey and laying the groundwork for future mapping efforts. Though still in process, this data will prove vital for understanding the cave’s full potential.

This expedition marked a significant milestone in exploring Thailand’s Satun region, proving that the area holds vast, untapped potential for cave diving and archaeological discovery. The Bottomline Projects team, supported by XDEEP ESP, not only pushed the limits of known cave systems but also laid the groundwork for future expeditions.

Satun is fast becoming recognized as a world-class cave diving destination, and together with the local authorities, Bottomline Projects is leading the way in unlocking its secrets for future generations.