Where is the Gulf of Thailand?
The Gulf of Thailand forms part of the South China Sea in the Pacific Ocean. It is bordered by four countries:
- Thailand – to the north, west, and southwest
- Cambodia – to the northeast
- Vietnam – to the northeast
- Malaysia – at the southern tip of the Malay Peninsula
The gulf stretches about 830 km long and averages 385 km wide, making it one of Southeast Asia’s most important coastal features.
Why is it Called the Gulf of Thailand?
The gulf was historically known as the Gulf of Siam (Siam being the former name of Thailand). The name reflects coastline distribution:
- Thailand: 1,560 km
- Cambodia: 460 km
- Vietnam: 230 km
- Malaysia: 150 km
Since Thailand has the longest stretch of coastline along the gulf, the body of water is named after the country.
Geographic and Environmental Features
- Formation: Shaped about 10,000 years ago after the last Ice Age, when glaciers melted and flooded the Chao Phraya River valley.
- Depth: Relatively shallow, averaging 45 meters.
- Salinity: Low, due to major rivers like the Chao Phraya and Mae Klong bringing nutrients and sediments.
🌊 Unique Ecosystem:
- Whale sharks (juveniles)
- Bull sharks and seahorses
- Mobula rays
- Colorful coral reefs
The nutrient-rich waters make the gulf an ideal environment for thriving marine life.
The Largest Island in the Gulf of Thailand
The gulf’s largest island is Phu Quoc (Vietnam), covering 570 km²—about two-thirds the size of Singapore. Located near the Mekong Delta, it is Vietnam’s biggest island, celebrated for its pristine beaches, diving spots, fish sauce production, and Phu Quoc pepper farms.
The Most Beautiful Islands in the Gulf of Thailand
📌 In Thailand
- Koh Samui – Luxury resorts, palm-fringed beaches, lively nightlife.
- Koh Tao – World-class diving and snorkeling, also called “Turtle Island.”
- Koh Phangan – Home to the legendary Full Moon Party.
- Koh Samet – Close to Bangkok, perfect for weekend getaways.
📌 In Cambodia
- Koh Rong – Clear waters, vibrant nightlife, backpacker-friendly.
- Koh Rong Samloem – Peaceful, eco-focused escape.
- Koh Ta Kiev – A hidden gem with raw natural beauty.
📌 In Vietnam
- Phu Quoc – Star attraction with beaches, coral reefs, diving, and fresh seafood.
Mu Ko Ang Thong – The Jewel Marine Park
Near Koh Samui lies the Mu Ko Ang Thong National Marine Park, a breathtaking archipelago of 42 islands.
🌿 Highlights:
- Dramatic limestone cliffs and jungle-covered hills
- Coral reefs and lush tropical forests
- Wildlife such as dolphins and wild boars
🌊 Activities: Snorkeling, kayaking, hiking, and even camping. Overnight stays in bungalows or campsites make it a perfect short escape.
Final Words
The Gulf of Thailand is more than just a body of water—it’s a living ecosystem and a gateway to some of Southeast Asia’s most beautiful islands. Whether you’re drawn to Koh Samui’s luxury, Koh Rong’s rustic charm, or Phu Quoc’s natural wonders, this gulf promises unforgettable adventures.
👉 Best Season: December to April for sunny skies and calm seas.
Pack your swimsuit and get ready to discover the hidden beauty of the Gulf of Thailand! 🌴
