Diving in Thailand: Gulf of Thailand vs. Andaman Sea – Which is the Best?
Thailand is one of the world’s best diving destinations, but which region is better – the Gulf of Thailand or the Andaman Sea? Both offer stunning underwater landscapes, but they differ in conditions, marine life, and top dive sites. In this guide, we compare the two areas to help you choose the best spot for your next diving adventure!
1. Location & Geography
- Gulf of Thailand: Located on Thailand’s east coast, bordered by Cambodia and Vietnam. Popular dive regions include Koh Tao, Koh Phangan, Koh Samui, and Koh Chang.
- Andaman Sea: Situated on Thailand’s west coast, bordering Myanmar and the Nicobar Islands. The most famous dive destinations include Similan Islands, Koh Phi Phi, Koh Lanta, and Phuket.
2. Weather & Diving Conditions
- Gulf of Thailand: Best diving season for Koh Chang (Koh Tao and Koh Samui are in a different climate zone): October to May. Water temperatures range between 28-32°C year-round, and diving conditions are mostly calm with mild currents. However, due to the relatively shallow depth, conditions are highly influenced by weather and tides. During the monsoon season, especially from late August to late September, waves can reach up to 3 meters.
- Andaman Sea: Best diving season: October to May. Many dive sites close during the monsoon season (June–September). Visibility can reach up to 30 meters, but stronger currents are common.
3. Marine Life
- Gulf of Thailand: Famous for whale sharks, barracudas, groupers, nudibranchs, and beautiful coral gardens.
- Andaman Sea: Home to larger species such as mantas, whale sharks, leopard sharks, and dramatic underwater rock formations.
4. Best Dive Sites
| Dive Site | Region | Highlights |
|---|---|---|
| HTMS Chang Wreck | Gulf of Thailand (Koh Chang) | Thailand’s largest wreck, perfect for wreck diving. Often home to whale sharks, sea turtles, large barracudas, and many other fascinating marine species. |
| Hin Luk Bat | Gulf of Thailand (Koh Chang) | A stunning dive site with diverse topography, large rock formations, and a variety of reef fish. Ideal for experienced divers and macro photographers. |
| Chumphon Pinnacle | Gulf of Thailand (Koh Tao) | Known for whale shark sightings and large schools of fish. |
| Hin Daeng & Hin Muang | Andaman Sea | Manta rays and whale sharks along dramatic steep walls. |
| Richelieu Rock | Andaman Sea | One of Thailand’s best dive sites, featuring incredible marine biodiversity. |
5. Wreck Diving – Gulf of Thailand or Andaman Sea?
- Gulf of Thailand: A paradise for wreck diving! The HTMS Chang Wreck is a must-dive site.
- Andaman Sea: Fewer wrecks but stunning underwater rock formations.
6. Who Should Dive Where?
- Gulf of Thailand: Ideal for all types of diving courses. Koh Tao and Koh Chang are perfect locations for beginner and advanced courses. Especially in Koh Chang, there is no mass diving tourism, allowing for relaxed and personal diving experiences.
- Andaman Sea: Better suited for advanced divers, especially for drift diving and encounters with large pelagic species.
7. Conclusion – Where Should You Dive?
- Gulf of Thailand: Best for beginners, wreck divers, and relaxed diving.
- Andaman Sea: Perfect for experienced divers looking for dramatic walls, big marine life, and strong currents.
Both regions have their charm – it all depends on what you’re looking for! If you’re seeking a combination of wreck diving, coral reefs, and relaxed dives, Koh Chang is the perfect choice!
