Hydronauts Diving Resort

Hydronauts Diving Resort is situated in Chalok Bay on the island of Koh Tao, providing a direct link to the most diverse reef systems in the Gulf of Thailand. The centre operates as a seaside resort, meaning your transition from the classroom to the boat is seamless, with departures occurring directly from the beach.

The resort is designed to support all stages of a diver's progression, from those taking their first breaths underwater to technical divers looking to master sidemount or wreck penetration. By combining professional RAID instruction with a relaxed resort atmosphere, it provides a structured environment for both holiday divers and those on a training programme.

The team consists of RAID-certified instructors who prioritise safety and the development of precise buoyancy and navigation skills. To ensure close supervision and individualised coaching, the centre maintains a strict ratio of no more than four divers per guide.

Environmental stewardship is integrated into the centre's operations through a partnership with Global Reef. The team works to protect the local Koh Tao ecosystems by minimising plastic use and utilising digital learning materials for all RAID courses.

Hydronauts offers the complete range of RAID certifications, starting with the Try Dive and Open Water Diver courses. For those looking to extend their capabilities, the Explorer 30 and Advanced Open Water Diver programmes are available, alongside specialised Nitrox (EAN) training.

Advanced divers can pursue technical and specialty skills including Deep 40, Sidemount, and Advanced Wreck. The centre also provides professional pathways through Divemaster Training, the Instructor Development Program, and Instructor Crossover courses, as well as essential First Aid & Oxygen Provider training.

Boat trips depart from the beach at Chalok Bay, with morning departures at 06:15 and afternoon departures at 11:45. The boats are equipped with a shaded upper deck for relaxing between dives and dedicated dry spaces to keep your belongings secure.

On board, you will find refreshments to keep you hydrated throughout the day. The fleet services a variety of sites across the island, including the deep pinnacles and the recent wreck sites, with Nitrox available for use.

The centre is fully equipped for both recreational and technical diving. For those looking to upgrade their experience, the shop provides high-quality backplate and wing configurations for a more streamlined profile. Full kit hire is available, including regulators, wetsuits, fins, masks, and weights.

For those managing their own equipment, dive computers are also available for rental. On-site facilities include a dedicated training pool for skill practice and rinsing areas for your gear.

The reefs around Koh Tao are vibrant, with large schools of fusiliers (Caesio), carangues, and barracudas frequently moving through the water column. You will often encounter various species of reef fish, including butterflyfish (Chaetodon), angelfish (Pomacanthidae), and parrotfish (Calotomus) navigating the coral heads.

On the sandy bottom and around the ledges, you can regularly spot southern stingrays (Hypanus americanus), blue-spotted stingrays, and various species of turtles, including the green turtle (Chelonia mydas) and hawksbill turtle (Eretmochelys imbricata). Blacktip reef sharks (Carcharhinus melanopterus) are also known to visit the deeper sections of the pinnacles.

For those interested in macro life, the crevices and corals host a wealth of smaller creatures. Look for nudibranchs, gobies (Gobiidae), ghost shrimps (Caridea), and various crustaceans like crabs (Brachyura) and hermit crabs. You may also find octopus (Octopus vulgaris), cuttlefish (Sepiidae), and various species of scorpionfish (Scorpaenidae) tucked away in the reef structure.

The seabed and coral gardens are beautifully decorated with gorgonians, sea whips, sponges (Porifera), and various hard and soft corals (Alcyonacea), providing a complex habitat for the local marine life.

The diving environment in Chalok Bay and the surrounding areas is generally characterised by calm conditions. The sites vary from shallow, sheltered bays like Mango Bay and Aow Leuk, which are ideal for relaxed diving, to more open pinnacles that may experience more movement in the water.