Master Divers — Weekly Dive Report 8.12 – 14.12

Period: Monday 8.12 – Sunday 14.12
Location: Koh Tao, Gulf of Thailand

We’ve just finished a beautiful week here on Koh Tao, but still remember that early- to mid-December often reflects the northeast-monsoon influence: some wind, possible rain showers, and a decent chance of swell are still predicted. That said, there are usually calm windows and protected dive sites can still offer good conditions. Here’s a week-ahead outlook to help you plan your week of diving.

☔ Rain & General Weather

December around Koh Tao typically sees intermittent showers, not constant rain. The likelihood of rain exists, but there may be good, clear windows especially in the mornings or between weather systems.
Showers could be more frequent mid-week depending on whether passing systems will hit Koh Tao straight on or not. Expect variability: some days might remain mostly dry with sun or light clouds; others might bring moderate rain or showers.
Rain + wind may affect the surface conditions more than they affect the conditions under water.

💨 Wind Conditions

Moderate to occasionally stronger winds are likely this week. In December, northeast-to-east trade winds remain common, which can lead to choppy seas on exposed coasts.
Wind strength may vary daily; sheltered western and southwestern bays of Koh Tao remain your best bet if winds pick up.
As always, boat transfers and surface conditions should be monitored, especially on windier days.

🌊 Swell & Waves

Expect moderate swell most days, with waves that can vary depending on wind strength and direction. Swell direction likely from the northeast or east, consistent with monsoon winds.
On calmer days, the conditions should be good enough to utilize dive sites all over the island. On more breezy days, protected bays should offer manageable sea states and safe entries/exits.
On windier or rainy days, especially with swell, surge and surface chop may impact shallower reef sites or shallow entry points.

👁️ Underwater Visibility & Dive Conditions

With mixed weather (wind, rain, swell), visibility may be variable; from fairly good in calm periods to modest on rougher days when surface conditions stir up sediment.
Best visibility expected after periods of rain/wind calm-down and on deeper or more sheltered reefs.
As always, we’ll pick our dive sites day by day at Master Divers to aim for the best available conditions.

🐠 Marine Life & Dive Outlook

This last week we’ve had some really nice encounters with whale sharks hanging around our island again, and some lucky divers even spotted a dolphin at Chumphon pinnacle at the tail end of last week! Definitely try to sign up for any of our morning dives headed out towards Chumphon and Southwest for the best chances of encounters like this.

Even if surface conditions are mixed, marine life often adapts. Our usual suspects will still be a safe bet; nudibranchs, pufferfish, blue spotted stingrays and the odd turtle should be possible to see.
Calm intervals present great windows for macro photography and reef exploration; rougher periods might attract larger, more mobile species.

🧭 Dive Planning Advice

Wetsuit: The water remains warm so a 3 mm shorty or rashie should suffice, but with the potential of colder currents coming through if you tend to get cold or are doing several dives each day a full 3mm wetsuit might be better suited.
Timing: Aim for morning dives or dive sites on the more sheltered west/south-west side on potentially breezy days.
Safety: Monitor surface and sea state conditions; if wind and swell build, opt for calmer sheltered sites, delay entry or choose deeper dives.
Flexibility: Be ready to adjust dive plans, unpredictable weather means adaptability is key.

As always, check your weather apps daily to get the latest data to plan accordingly. We use Windy.com, Windguru and the Thailand Metereological Department. See you down below!

Koh Tao Weekly Dive Report 8.12 – 14.12

Master Divers — Weekly Dive Report 8.12 – 14.12