Koh Samui is Thailand's second-largest island, sitting in the Gulf of Thailand. Its beaches are some of Southeast Asia's most developed tourist destinations — Chaweng and Lamai offer the full range of beach clubs, restaurants, and water sports. The island's interior is lush jungle with waterfalls.
Koh Samui's Gulf of Thailand position means it operates on an opposite monsoon cycle to Phuket. The east coast (Chaweng, Lamai) is best November–April; the west coast (Mae Nam, Bang Po) is sheltered during northeast monsoon. Choose your beach based on season.
Koh Samui does not have significant sargassum issues. The Gulf of Thailand's calmer waters mean less seaweed washing ashore compared to open ocean beaches. Jellyfish can appear seasonally, particularly box jellyfish — always check with locals before swimming.
Koh Samui was visited by Arab and Chinese traders sailing the Gulf of Thailand for centuries before modern development — the island's coconut plantations, which carpeted it throughout the 19th and early 20th centuries, supplied the maritime trade networks of Southeast Asia with copra shipped to markets across the region. The island remained largely isolated from the outside world until the first regular boat service from the mainland was established in the 1920s, with no paved roads until the 1970s and no airport until 1989. The layered cultural influences visible in Koh Samui's Buddhist temples and Chinese shrines reflect the island's position at the intersection of Indian Ocean, South China Sea, and Gulf of Thailand maritime trade routes that shaped Southeast Asian civilization for two millennia.
"Deep calls to deep in the roar of your waterfalls; all your waves and breakers have swept over me." — Psalm 42:7Live seaweed levels, surf, water quality and hotel deals — updated daily. Free.
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