Shark Island lives up to its dramatic name – this granite islet off Koh Tao’s southeast coast delivers some of the most exhilarating dives in the Gulf of Thailand. Rising sharply from the seabed like a shark’s fin (hence the name), the site combines strong currents, deep walls, and stunning soft coral gardens. About 65% of advanced divers visiting Koh Tao rank it among their top three dive sites. While not for beginners, those with proper training will find an underwater playground teeming with life and adventure. Let’s break down what makes Shark Island so uniquely thrilling.
Currents That Demand Attention
Unlike Koh Tao’s calmer bays, Shark Island often has strong currents that sweep nutrients (and divers) around its granite formations. These currents create what locals call “underwater highways” for pelagic fish. During my last dive here, we hooked onto rocks to watch four blacktip reef sharks cruise the current line. Dive shops report that about 40% of planned Shark Island dives get redirected due to extreme currents – always have a backup site in mind. When conditions align, though, you get that perfect drift dive where you barely need to kick.
A Coral Rainbow at Depth
Below 10 meters, Shark Island transforms into a living art gallery. Purple soft corals wave like trees in the current, while giant barrel sponges big enough to hide in dot the landscape. The real showstoppers are the gorgonian sea fans – some stretching over 2 meters wide. Marine surveys show 58 coral species here, with particularly healthy soft coral coverage compared to other Thai sites. These vibrant structures attract clouds of anthias fish that look like living confetti when backlit by sunlight.
The MV Trident Wreck Challenge
Shark Island offers the MV Trident wreck at 36 meters for technical divers. This former German coastguard vessel was sunk in 2010 and now hosts giant grouper and schools of batfish. The wreck’s depth and frequent strong currents make it strictly for advanced divers – local shops require at least Deep Diver certification plus 30 logged dives. About 15% of Shark Island dive trips include the wreck when conditions permit. Its cargo holds and swim-throughs offer proper adventure for those qualified.
Unexpected Big Encounters
While you might not see sharks every time (despite the name), Shark Island delivers regular big animal encounters. Whale sharks visit seasonally – about 12% of dives between March and June spot them. You’ll commonly meet Napoleon wrasse, which is the size of refrigerators and titan triggerfish, during their aggressive nesting season. The site’s resident school of yellowtail barracuda, numbering about 200 individuals, forms a shimmering silver vortex that’s become iconic for underwater photographers.
Perfect for Advancing Skills
Shark Island serves as Koh Tao’s natural classroom for advanced training. Many dive shops use it for Deep Diver certifications (18-30m range) and Drift Diver specialties. The varying conditions also make it ideal for buoyancy challenges – you’ll need precise control to hover near those delicate corals in the current. About 70% of Advanced Open Water students who dive here report it was their most valuable training dive, precisely because it pushes comfort zones in a controlled way.
Conclusion
Shark Island rewards divers who come prepared with skills and respect for its conditions. The currents that make it challenging also bring incredible marine life, while the depth range offers something for advanced divers and techies alike. It’s where you might battle an intense downcurrent one minute, then drift effortlessly past a whale shark the next. Remember to check conditions with local guides, keep your air supply in mind, and enjoy the ride – Shark Island delivers stories worth sharing over post-dive beers.