Koh Tao Dive Report 24.11 – 30.11

Master Divers — Koh Tao Dive Report 24.11 – 30.11

Period: Monday 24.11 – Sunday 30.11
Location: Koh Tao, Gulf of Thailand

Next week will likely continue showing typical late-November monsoon. Expect a mix of wind, rain, and some rougher sea conditions as the northeasterly monsoon starts gaining strength again. Dive planning will need to account for shifting surface conditions and potential surge.

☔ Rain Forecast

• Rain continues to be a possibility during this week. Based on TMD forecasts, isolated heavy rain and thunderstorms are expected from 27–30 November, particularly in the lower Gulf region.
• These showers could be more than just brief afternoon rain, heavier downpours are possible, especially when combined with swell or surface wind.
• For divers: morning dives may still offer better chances for reasonable conditions, but by the end of the week some caution is required, especially with potential strong showers and changing sea state.

💨 Wind Conditions

• Forecasts indicate a rather strong northeasterly monsoon through the latter part of the week (27–30 Nov).
• Wind speeds may reach 20–35 km/h or more, especially during potential thunderstorms and out in the open water.
• This wind direction could drive more chop on exposed eastern dive sites, and boat transfers may become more challenging later in the week. Remember to take your seasickness pills!
• Diver caution: expect rougher conditions, and verify with your dive center whether site access may be limited.

🌊 Swell & Waves

• With the strengthening NE monsoon, wave heights are expected to increase. Waves could reach 2–3 meters or more in thundershower conditions.
• This means potential for surge, swell, and rough surface water, especially on exposed reefs and nearshore areas.
• Dive strategy: opt for more protected dive sites when possible; avoid exposed shallow or surge-prone zones during peak wind or swell. With the wind forecast being what it is, it will probably be sheltered sites on the south, south-west side of the island

🌙 Tides & Currents

• Standard tidal patterns (two high, two low) should continue, but stronger wind and wave action may generate more significant surface currents or surge, particularly during windier mid- to late-week periods.
• Dive planning should be flexible: prioritize sites that are safer under rougher conditions, and be prepared to adjust based on real-time sea behaviour.

👁️ Underwater Visibility

• Given increased wind and rain risk, expect visibility to be more unpredictable than in a calm season. We’re probably looking at the same low visibility conditions as last week again, with around 2 meters being the average.
• On days with heavy rain + surge (especially end of week), sediment runoff and wave-driven turbidity might reduce underwater clarity further.
• Mornings may still offer the best visibility, especially at protected or deeper sites. Dive guides should actively choose sites for optimal conditions day-to-day.

🐠 Marine Life Highlights

• With some of the week potentially rougher and more current-driven, the chance to spot larger, mobile species like barracudas or rays may be higher..
• The more turbulent water could also stir up sand or small particles, making it a good week to look for macro life (nudibranchs, shrimps, hermit crabs) hiding in the reef.

🧭 Recommendations for Divers

• Wetsuit: Water temperature remains warm in November (around ~29 °C per seasonal averages).  A 3 mm shorty or rashie continues to be appropriate. Be wary of cooler currents, so if you’re prone to being cold, a full 3 mm might be advisable
• Dive Timing:
  • Early mornings are likely to be safest, especially mid-week.
  • Later in the week, consider sheltered dive sites or deeper dives to reduce risk from rough surface conditions.
• Safety:
  • Check with your dive operator on sea conditions each day — they may skip or modify site plans if wind and swell pick up.
  • Use good surface protocols (e.g., line signals, float markers) when transferring in potentially rough conditions.
  • Dive conservatively: if surface conditions look risky, delay or switch to more protected sites.

Dive safe — with challenging conditions it is important to remember your training and dive conservatively! 🐬

We base our forecasts on Windguru, Windy.com, and TMD guidance, but with Koh Tao’s everchanging weather forecast, you should always verify conditions before diving.