Ko Mai Si · Trat · Thailand
Koh Mai Si Beach
You'll step from the boat onto a crescent where hermit crabs outnumber footprints. The granite boulders framing each end glow amber in late afternoon, and the Gulf laps so gently you hear your own breathing.
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Live from Open-Meteo · sea surface temperature and wave data modelled at 1-km grid resolution for Koh Mai Si Beach. Numbers refresh at the hourly tick.
- Purity
- 0%
- Conditions
- 0%
- Crowd
- 0%
- Vibe
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The OnlyBeaches Index weighs four pillars against your chosen persona. Purity comes from water clarity and air-quality heuristics; Conditions from Open-Meteo waves, wind and temperatures; Crowd from historical patterns; Vibe from nearby events within 50 km. The score rebalances throughout the day.
You'll step from the boat onto a crescent where hermit crabs outnumber footprints. The granite boulders framing each end glow amber in late afternoon, and the Gulf laps so gently you hear your own breathing.
Photos
8 captures from Koh Mai Si Beach
About this beach
Where it is
Koh Mai Si Beach
Ko Mai Si, Trat, Thailand
11.7395°, 102.5320°
Top things to do
At Koh Mai Si Beach
Coral Gardens
Knee-deep reef on eastern shore
Granite Headlands
Amber boulders frame each end
Shallow Wading
Bathwater channels through sand bars
Solitary Sprawl
Unshaded sand under casuarina pines
Near this beach
Places, rentals, tours and events within walking and driving distance of Koh Mai Si Beach.
Questions people actually ask about Koh Mai Si Beach.
Is swimming safe at Koh Mai Si Beach?
Swimming at Koh Mai Si is generally safe during the dry season when seas are calm, though visitors should exercise standard precautions. The protected bay location offers shelter from strong currents, making it suitable for most swimmers. No lifeguards are present, so assess conditions yourself and stay aware of boat traffic from island-hopping tours. During monsoon months (May-October), conditions become unpredictable with rougher waves and reduced visibility. Wear water shoes as some areas have rocks and coral fragments. Always inform your boat operator before entering the water and don't swim alone.
What is the best time to visit Koh Mai Si Beach?
November through March offers the best conditions, with calm seas, minimal rainfall, and excellent underwater visibility for snorkeling. December and January are peak months with the most stable weather but also higher tour availability. April can be very hot but still enjoyable with fewer visitors. The monsoon season from May to October brings heavy rains and rough seas, making boat access unreliable or impossible. Visiting during weekday mornings provides the greatest chance of solitude, as most organized tours arrive mid-morning. Early season (November) and late season (March) offer good value with decent weather.
