Chumphon Pinnacle

Overview & Topography

Located 11 kilometres north-west of Koh Tao, Chumphon Pinnacle is widely considered the crown jewel of local diving in the Gulf of Thailand.

The site consists of one massive granite seamount that rises from a sandy sea floor at 36 metres to within 14 metres of the surface, surrounded by several smaller submerged boulders known as Barracuda Rock. The entire granite monolith is blanketed in a dense carpet of pink and sea-green carpet anemones (Heteractis magnifica) and sea anemone fish.

Detailed Dive Route & Navigation

• Descent: Negative or quick descent down the deep mooring line to the main pinnacle summit at 14m–16m to avoid surface drift.
• The Deep Base & Barracuda Rock (24m–35m): Drop down the northern or western sheer granite face into the deeper water. At 28m off the south-west ridge lies Barracuda Rock, where thousands of chevron barracuda and bigeye trevally form swirling silver tornados.
• The Mid-Water Ledges (18m–22m): Circle the main pinnacle ascending in a gentle corkscrew. Inspect deep crevices for giant grouper (Epinephelus lanceolatus) measuring over 2 metres in length and honeycomb moray eels.
• The Anemone Plateau & Safety Stop (14m–5m): Spend the final 15 minutes of the dive exploring the vast anemone gardens covering the crown at 14m. Cast your eyes upward into the open blue: Chumphon is Koh Tao’s prime hotspot for transient whale sharks (Rhincodon typus) filter-feeding near the surface.

Certification & Safety Rules

• Certification Level: Advanced Open Water (30m) recommended. Open Water divers are restricted to the 14m–18m summit and cannot access the deep base or Barracuda Rock.
• Currents & Visibility: Visibility averages 15m to 30m. Thermoclines are common between March and September, dropping water temperatures from 29°C to 24°C below 22m.
• Mooring Safety: Surface marker buoys (SMBs) are mandatory for all buddy pairs, as boat traffic around the pinnacle can be intense.

Technical Dive Profile & Navigation

1. Entry & Descent Mechanics

• Descent Method: Direct giant-stride or negative back-roll from the boat, descending along the shot line to prevent surface drift.
• Ear Equalization: Equalize continuously every 1 metre during the descent phase to prevent sinus or middle-ear barotrauma.
• Compass Heading & Navigation: Set a primary heading toward the main reef structure. Maintain buddy contact within 2 metres throughout the descent.

2. Deep Section & Gas Management (14m to 35m)

• NDL Discipline: At depths of 30m, your No-Decompression Limit ticks down rapidly. Monitor your dive computer continuously.
• The Craig Rule: Divers certified to Open Water level (18m maximum) must stay on the upper reef shelf and never follow advanced divers down past 18m.
• Turnaround Gas: Signal your buddy and start your ascent when the first diver reaches 110 bar (or one-third of usable cylinder capacity).

3. Ascent & 5m Safety Stop

• Ascent Rate: Ascend along the reef wall at a controlled rate not exceeding 9 metres per minute.
• Mandatory Safety Stop: Complete a strict 3-to-5-minute safety stop at 5 metres (15 feet) before deploying an SMB and surfacing with a 360-degree overhead scan.

Marine Life & Habitat Zones (Biologically Verified)

• Apex & Pelagic Predators: Whale Sharks (Rhincodon typus), Chevron Barracuda (Sphyraena qenie), Queenfish (Scomberoides commersonnianus).
• Reef Fish & Keystone Species: Titan Triggerfish (Balistoides viridescens), Pink Anemonefish (Amphiprion perideraion), Giant Grouper (Epinephelus lanceolatus).
• Macro Biodiversity & Benthic Invertebrates: Janss Pipefish (Doryrhamphus janssi), Nudibranchs (Phyllidia varicosa), Banded Boxer Shrimp.
• Elasmobranchs & Marine Reptiles: Whitetip Reef Sharks, Leopard Sharks (Stegostoma tigrinum), Green Sea Turtles, Blue-Spotted Fantail Rays (Taeniura lymma).