Master Divers — Koh Tao Weekly Dive Report
Period: Monday 12.01 – Sunday 18.01
Location: Koh Tao, Gulf of Thailand
Mid-January continues to reflect typical northeast monsoon conditions in the Gulf of Thailand. Expect a mix of cloud cover, moderate winds, scattered showers and variable surface conditions. Diving remains possible throughout the week, but conditions may change quickly, making daily site selection important.
☔ Rain Forecast
Scattered showers are expected throughout the week, consistent with Thai Meteorological Department guidance for this time of year.
Rain is not expected to be continuous, but passing showers may occur at any time, with a slightly higher chance later in the day.
Occasional heavier showers may temporarily affect surface conditions and underwater visibility.
For divers: mornings are generally the best window for calmer seas and reduced rain activity.
💨 Wind Conditions
Northeasterly winds are expected to dominate throughout the week.
Based on Windy and Windguru trends, wind speeds are likely to remain moderate, with occasional stronger periods, especially mid-week.
This wind direction can create choppier surface conditions on exposed eastern and northeastern coastlines. Western and southwestern bays are likely to remain more sheltered and suitable for diving.
Boat crossings may feel bumpy on windier days, so seasickness precautions are recommended.
🌊 Swell & Waves
With ongoing NE monsoon influence, moderate swell is expected.
Wave heights are likely to range around 1 to 2 meters, with short-period chop on top during stronger wind phases. Exposed sites may experience noticeable surge, particularly in shallower areas and along reef edges.
Dive strategy: sheltered sites on the west and southwest side of Koh Tao are still likely to offer the most consistent and comfortable diving conditions this week.
🌙 Tides & Currents
Koh Tao will continue to experience a standard semi-diurnal tidal pattern with two high and two low tides daily.
Wind-driven surface currents and localized surge may be present, particularly during stronger wind periods or around headlands. Dive planning should remain flexible, adjusting site choice based on real-time sea conditions.
👁️ Underwater Visibility
Visibility is expected to remain variable, typical for the monsoon season.
On calmer days and at protected or deeper sites, visibility may improve, while periods of wind, rain and swell can reduce clarity due to sediment movement and runoff.
At Master Divers, dive sites are selected day by day to ensure the best possible underwater conditions.
🐠 Marine Life Highlights
With some current, water movement and a bit of an algae bloom, there is a chance of encountering larger, mobile species such as barracudas, rays or even whale sharks, especially out by the deeper pinnacles where the usual big schools of fish are thriving as well these days.
Variable visibility also makes this a great week to slow down and focus on macro life. Keep a peeled eye!
🧭 Recommendations for Divers
Wetsuit:
Water temperatures remain warm at around 27 to 29 degrees Celsius. A 3 mm shorty or rashie is suitable for most divers, while those who feel the cold easily may prefer a full 3 mm or 5 mm wetsuit.
Dive Timing:
Morning dives are recommended when surface conditions are often calmer.
Sheltered west and southwest dive sites are likely to provide the most comfortable conditions this week.
Safety:
Be mindful of changing surface conditions and dive within your limits.
Listen carefully to dive briefings and be prepared to adjust plans if wind or swell increases.
Dive safe and enjoy the underwater season. 🐬
We base our forecasts on Windguru, Windy.com, and guidance from the Thai Meteorological Department. Weather around Koh Tao can change quickly, so always verify local conditions before diving.
