Why We Love Technical Deep Diving
There’s something mystical about deep diving. Beyond 60 meters (200ft), you’re entering another world – a quiet, untouched time capsule. Many of these places hold reefs and sunken vessels that are rarely visited, and some places may never have seen a diver’s torch. It’s the closest thing to otherworldy travel, exploring the silence of the deep.
Here are five of the most exhilarating technical diving sites around Pattaya and Samae San, where only the truly prepared should venture.
Top 5 Tech Dives in Pattaya Menu
1. The Samae San Hole – “The Deep Hole of Death” (100m)
Depth: 85–100m
Certification Required: Full Hypoxic TRIMIX
GPS: N12°32.322″ E100°57.605″
Why it’s legendary:
If you’re a certified technical diver looking for the ultimate challenge in Thailand, Samaesan Hole – also ominously known as “The Hole” offers one of the most extreme and hazardous underwater experiences on the planet.
Voted the world’s 5th most extreme dive site by Red Bull, this vertical underwater crater lies in the heart of a busy shipping lane between Ko Chuang and Ko Samae San. It drops dramatically to a depth of 99 meters, and it’s not just the sheer depth that earns its reputation – it’s the lethal mix of ferocious currents, limited visibility, and military history.
Originally used as a military ammunition dump, Samaesan Hole is marked on marine charts as an explosive dumping ground, littered with unexploded ordnance. Divers report spotting everything from rusted munitions to military waste – making it as dangerous as it is fascinating.
Above 60 meters, there’s little to see but steep slopes with soft corals and rocky outcrops with shifting sands and swirling currents at times. Below that, the true challenge begins. Proper trimix training, redundant gear setups, multiple dive computers, and powerful backup lights are essential. This is no place for casual divers or unprepared adventurers.
On top of the physical dangers, the dive site sits directly in a commercial shipping route, where massive oil tankers pass through daily—often crossing the depths of your final safety stops. Careless surfacing here could lead to catastrophic consequences.
For the few qualified to explore it, Samaesan Hole is Thailand’s ultimate technical dive: perilous, unpredictable, and unforgettable.
Pro Dive Tip: Slack water only. Anything else could end with you surfacing near Cambodia.
2. The Samaesan Cliff – Vertical Drop-Off (50–85m)
Also Known As: Sharkfin Deep Drop
Depth: Overhang at 50m, Seabed at 85m
Gas: Trimix or Deep Air (for experienced techies only)
Status: Technical Decompression Dive
Why it’s Epic:
An eerie underwater cliff face where schooling giant groupers, 2-meter cobias, and massive rays cruise through the blue. Begin at the 50m seabed and navigate west. A true “zen dive” for technical divers who enjoy compass work and dreamlike marine life in deep water.
Pro Dive Tip: Slack water dive only. Expect surge and reduced bottom times.
3. Pak-1 Wreck – The Vertical Ghost Ship (42–60m)
Also Known As: Koho Maru-5 / Former Vertical Wreck
Depth: 42m seabed; previously vertical at 60m
Gas: Nitrox 28–30; Deco mixes + O₂
Status: Technical Decompression Dive
Why it’s Unforgettable:
Originally sank in 1996 during a violent storm with tragic loss of life. Famously stood vertically underwater for 6 years – stern on the seabed and bow just 5m below the surface – before mysteriously re-floating and drifting toward Cambodia. Eventually, the Thai Navy towed and re-sank her.
Today, Pak-1 lies at a much safer 42m but is still teeming with penetration opportunities, particularly in the aft crew quarters. But beware – below the thermocline, viz drops dramatically and silt lies in wait.
Pro Dive Tip: Veer off the mooring to the radar mast (~25m) for an epic entry. Bring multiple torches and reels.
H.T.M.S. Sarasin – Thai Navy Sub Chaser (43m)
Also Known As: Sarasin Wreck
Depth: Seabed at 43m; wreck top at 35m
Gas: Nitrox 26%; Deco mixes + O₂
Status: Technical Decompression Dive
Why it’s Unforgettable:
Sunk as part of a live-fire missile exercise, this former US Navy PC-461 Class Sub Chaser now lies on her port side, cloaked in murky darkness and strewn with ghost nets. While some entry points exist, the wreck remains largely unexplored, presenting a challenge to technical divers hungry for new frontiers.
Pro Dive Tip: Bring cutting tools and reel. No surface buoy – grapple entry required.
5. The Hardeep Wreck – A Legendary Starting Point (28m)
Also Known As: SS Suddhadib
Depth: Seabed at 28m
Gas: Nitrox 36%; Deco mixes + O₂
Skill Level: Entry-Level Tech / Advanced Wreck
Why it’s Rite of Passage:
While not as deep as the others, The Hardeep Wreck is a must-dive wreck and the ideal starting point for technical wreck training. With multiple penetration routes, strong currents, and history dating back to World War II, it teaches buoyancy, silt management, and navigation in a real-world scenario.
Pro Dive Tip: Dive this site before taking on the deeper monsters. Great for sidemount or intro tech dives.
Final Thoughts
Pattaya and Samae San are home to some of Southeast Asia’s most thrilling and underrated technical dive sites. Whether you’re into penetration dives, trimix exploration, or brushing against the edge of safe diving limits -this region delivers.
But remember:
⚠️ These are not recreational sites.
Prepare. Train. Equip. Dive with professionals. And always respect the deep.
