To protect the marine environment, the Thai Ministry of Natural Resources and Environment has introduced strict new guidelines for divers and snorkelers.

The stricter rules, which will apply from April 22, 2025, aim to protect coral reefs and sensitive marine ecosystems by setting clear standards for diving and snorkeling activities.

These measures are legally binding under the Marine and Coastal Resources Management Act and apply nationwide for five years.

Snorkelers and freedivers

All dive operators must now ensure that every dive trip is accompanied by a certified dive instructor or assistant. When snorkeling near coral reefs, all guests must be provided with life jackets and wear them at all times, unless they hold a recognized freediving certification.

Dive briefings

Before any activity begins, dive guides must inform divers and snorkelers about applicable laws and responsible diving practices. In protected areas – such as national parks or designated marine protected areas – all additional legal regulations must also be clearly explained.

Diver-to-guide ratio: 4 to 1

In scuba diving, one dive guide may supervise up to four participants. In snorkeling and freediving, one instructor may supervise up to 20 people; if this number is exceeded, additional instructors or assistants are required.

For introductory dives, a stricter instructor-to-participant ratio of one instructor per two participants applies. Certified diving courses may be conducted with an instructor-to-participant ratio of one instructor per four participants, provided the activities comply with coral reef protection regulations.

Not photography for beginners

Photography during training or instructional dives is prohibited unless conducted by a qualified diver who holds an Advanced Open Water certification (PADI, SSI, or equivalent) or has logged at least 40 dives. Proof of certification or participation in a recognized underwater photography course must be presented upon request.

Only divers who meet these requirements are permitted to carry cameras during recreational dives. A valid diving certificate or dive log must be presented to the authorities upon request.

Keep your distance

Divers and snorkelers must maintain a distance of at least two meters from coral reefs to avoid direct contact. Dive and snorkel guides are required to explain proper buoyancy control to tourists and only allow experienced divers access to coral reefs. Behaviors that stir up sediment—such as clumsy fin control—are prohibited, as they can suffocate the coral and cause permanent damage.

Do not touch

Various activities are strictly prohibited in coral reef areas. Dive guides are not allowed to move, touch, or present corals, marine animals, or other marine life to tourists. Any contact with marine organisms is forbidden.

Feeding fish, littering, and any disturbance of reef habitats are prohibited. Underwater walks, including Sea Walkers and other seabed activities, are also prohibited in coral zones.

Enforcement and penalties

If a tourist does not follow instructions – for example, refuses to wear a life jacket or does not touch coral – their activity must be stopped immediately. Tour operators are required to report such violations promptly to the relevant marine or national park authorities.

Dive guides and instructors who fail to enforce these rules may lose their certification or operating license. These restrictions do not apply to academic research or conservation dives conducted under official supervision.

Thailand's commitment to marine conservation

These regulations underscore Thailand's commitment to protecting its marine ecosystems and promoting responsible tourism. Divers are strongly urged to familiarize themselves with the new rules and to work exclusively with certified operators who fully comply with national standards.

For more information about diving on Thailand's vibrant reefs, contact the experts at Diveplanit Travel. diveplanit.com/thailand