Koh Chang offers a wide selection of professional dive schools that will provide you with a safe and exciting underwater experience. Here are some of the best options:

1. Koh Chang Divers Co Ltd - This dive school has an excellent reputation among tourists. With a rating of 4.9 out of 5, Koh Chang Divers offers quality diving courses and expeditions. Instructors, such as Sean, are praised for their professionalism and commitment. The school organizes dives around the island, where you can see fascinating marine species such as black sharks and barracuda.

2. BB Divers PADI dive center - Another great option with a rating of 4.7, BB Divers offers a variety of courses, from basic Open Water Diver to more advanced courses. Instructors such as Adam, Markus and David are highly rated for their competence and friendly approach. The school organizes expeditions to interesting dive sites, including a sunken shipwreck.

3. Chang Diving Center - With a rating of 4.8, this dive school is highly regarded for its professionalism and concern for the environment. Instructors like Pern and Andi are praised for their patience and ability to impart knowledge. Chang Diving Center offers specialized courses, such as wreck diving and deep diving.

4. Thai Ocean Academy Koh Chang - With a perfect 5.0 rating, this school stands out for its unique approach to customers. Instructors, like Trent, are highly regarded for imparting extensive knowledge and providing a sense of security. The school offers courses ranging from basic OWD to advanced specializations.

5. The Scuba Squad Ko Chang - Also with a 5.0 rating, this dive school is praised for its professionalism and friendly atmosphere. Instructors such as Marcus and Sanka are highly regarded for their ability to create a safe and comfortable environment for divers of all levels.

All of the aforementioned schools offer modern and well-maintained equipment, which is crucial for divers' safety and comfort. Prices for courses and expeditions are comparable, but it is worth noting additional services, such as transportation to and from the hotel or meals on the boat, which may be included in the price with some operators.

When choosing a dive school, pay attention to the experience of the instructors, the size of the groups (smaller groups provide a more personalized approach) and the reviews of other divers. Regardless of your choice, any of these schools will provide you with an unforgettable underwater experience on Koh Chang.

Koh Chang and the surrounding islands offer a number of fascinating diving and snorkeling sites, each with unique characteristics and underwater attractions. Here are some of the best locations:

1. HTMS Chang Wreck - This is one of the most popular dive sites in the area. The sunken warship lies at a depth of about 30 meters and is home to a variety of marine life. It is an ideal site for divers with Advanced Open Water certification or higher. The wreck is accessible year-round, but the best visibility is from November to April.

2. Hin Luk Bat - This underwater rock formation is known for its rich marine life. Shoals of colorful fish, moray eels and sometimes even reef sharks can be found here. The site is suitable for both beginners and advanced divers, with depths ranging from 5 to 25 meters.

3. Hin Raab - This site is famous for its impressive coral formations and variety of fish species. It is an ideal snorkeling site for beginners, and also offers interesting dives for more experienced divers.

4. Koh Rang - This small island in Mu Ko Chang National Park offers some excellent diving and snorkeling sites. The waters around Koh Rang are crystal clear and the coral reefs are in excellent condition. Many species of tropical fish can be seen here, as well as larger creatures such as sea turtles and stingrays.

5. Koh Kra - This remote island offers some of the best diving in the region. The waters are usually very clear and the marine life is extremely rich. This place is ideal for experienced divers looking for adventure.

It is worth remembering that the availability of some sites may depend on the season and weather conditions. The best season for diving on Koh Chang is from November to April, when the sea is calm and visibility is best. During the other months, some sites may be inaccessible due to strong currents or reduced visibility.

When diving or snorkeling on Koh Chang, you can see many fascinating sea creatures. Among them are:

• Colorful reef fish, such as clownfish, parrotfish and hornfish
• Larger fish, including barracuda, tuna and sometimes reef sharks
• Sea turtles, especially around Koh Rang
• Octopuses and squid
• Starfish and sea urchins
• A variety of coral species

Remember that when diving and snorkeling, it is important to follow the rules of environmental protection. Don't touch coral, don't take anything from the seabed and avoid using sunscreen, which can harm coral reefs.

Whether you are a novice snorkeler or an experienced diver, the waters surrounding Koh Chang offer unforgettable underwater experiences. Each site has its own unique character and provides opportunities to explore the fascinating world below the surface.

To fully enjoy your underwater adventures on Koh Chang, there are a few practical tips to consider:

1. the best time for diving and snorkeling:
   • The season from November to April offers the best conditions: calm seas and excellent visibility.
   • During the other months, conditions may be less predictable, but you can still find good dive sites.

2 Choosing a dive school:

• Check the school's certifications and reputation before booking.
• Compare offers from different schools, paying attention not only to price, but also to group size, equipment quality and instructor experience.
• Schools such as Koh Chang Divers Co Ltd, BB Divers PADI dive center or Chang Diving Center have excellent reviews and offer a wide range of courses and expeditions.

3 Safety:

• Always dive with a licensed instructor or guide, even if you have experience.
• Make sure you know the dive plan and safety procedures before diving.
• Check your equipment regularly and don't hesitate to ask about its condition at the dive school.

4 Protect the environment:

• Use coral reef-friendly sunscreen.
• Don't touch or pick up anything from the seabed.
• Avoid standing on corals, even if they appear dead.

5 Prepare for snorkeling:

• If you plan to snorkel a lot, consider buying your own mask and tube for better fit and hygiene.
• Use UV-filtered shirts to avoid sunburn during long sessions in the water.

6 - Diving courses:

• If you are inexperienced, consider an introductory course (Discover Scuba Diving) or a full Open Water Diver course.
• For experienced divers, Koh Chang offers opportunities to gain specializations such as wreck diving or deep diving.

7 Costs:

• Prices for courses and diving expeditions are comparable between schools, but can vary depending on the season.
• Typically, an OWD course costs about 14,000-16,000 baht, and a single dive costs about 2,500-3,000 baht.
• Some schools offer packages, which can be more cost-effective for longer stays.

8 Accommodation:

• Choose a hotel or resort close to the beach, from where you can easily get to the dive schools.
• Some schools, like Thai Ocean Academy Koh Chang or The Scuba Squad Ko Chang, offer transportation to and from the hotel.

9 Health:

• Make sure you are in good health before diving.
• If you have any doubts, consult your doctor before you go.

10. documentation:
    • Take your dive certificate and logbook with you if you have them.
    • Consider purchasing dive insurance for the duration of your stay.

Remember that scuba diving and snorkeling is not only a sport, but also an opportunity to learn about the fascinating underwater world. Approach these activities with respect for the environment and enjoy every moment spent in the crystal clear waters of Koh Chang.

Whether you are a novice snorkeler or an experienced diver, the waters surrounding Koh Chang offer an unforgettable experience. With professional diving schools, abundant marine life and beautiful coral reefs, this Thai island is a true paradise for water sports enthusiasts. Dive into the blue waters of Koh Chang and discover the magical world that awaits beneath the surface!