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Siam Bay, Phuket in Thailand

Siam Bay on the western side of Ko Racha Yai Island in Thailand is a popular dive site nestled in a large bay. The sandy bottom is adorned with scattered coral and rocks, creating an underwater landscape that divers find captivating. In the heart of the bay, divers can explore Thai palatial houses, ethnic objects, and even encounter underwater sculptures of elephants, all at depths ranging from 20m to 25m.

Diving in Siam Bay is a treat for the senses, as the extensive coral beds showcase a vibrant array of marine life. Divers will be delighted by the colorful damsels, butterflyfish, snappers, and vibrant coral formations. Keep an eye out for majestic sea turtles gracefully gliding through the waters. Additionally, schools of Yellowfin Snappers and large groupers add to the diversity of marine species found here.

With a visibility of 13m and a maximum depth of 15m, Siam Bay is perfect for beginner divers. Its close proximity to ATM and the Phuket Province provides easy access for divers to conveniently enjoy this remarkable dive site.

Optimize your diving experience in Thailand by exploring the wonders of Siam Bay.

Diving Conditions Score for Siam Bay, Phuket in Thailand

6.7
Above Average

Decent conditions, proceed with caution.
The score is based on a calculation of the current weather and sea conditions.

Dive Site Overview for Siam Bay, Phuket in Thailand

Depth

15m

Visibility

13m

Experience Level

beginner

Weather Conditions for Siam Bay, Phuket in Thailand

Wave Height

1.38m

Wind Speed

10 m/s

Water Temp

29.7°C

Visibility

15km

Cloud Cover

57.5%

Wave Period

5.65s

Air Temperature

20°C

Precipitation

0 mm

Detailed 7-Day Diving Forecast for Siam Bay
Alpha

Dive Score Chart for Siam Bay

Best time to dive: 6:00 with score 6.806666666666667/10. Water conditions: Waves 1.38m, Wind 10 m/s.Best night dive time: 0:00 with score 6.306666666666667/10.

Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.

Sunrise at Siam Bay: 06:00
Sunset at Siam Bay: 18:00

Optimal diving conditions at Siam Bay are affected by daylight hours. Sunrise occurs at 06:00 and sunset at 18:00, which impacts visibility and water temperature for scuba diving and snorkeling.

🌞
Best Overall
6:00

Score: 6.8/10
Waves: 1.38m (8s), Wind: 10 m/s

🌙
Best Night
0:00

Score: 6.3/10
Waves: 1.38m, Wind: 10 m/s

Seasonal Analysis for Siam Bay, Phuket in Thailand
Alpha

Historical patterns and best seasons for diving at Siam Bay, Phuket in Thailand

The dive score combines all factors to rate overall diving conditions throughout the year. Higher scores indicate better diving conditions.

Monthly Dive Score Analysis - Seasonal Diving Conditions

Higher values indicate better diving conditions

Seasonal DiveScore Chart

This chart displays monthly diveScore data throughout the year, showing seasonal patterns. The data is presented as a bar chart with an overlaid line graph.Dive scores range from 1 to 10, with 10 being optimal conditions.

Higher values indicate better diving conditions

Best Season for Siam Bay, Phuket in Thailand

Winter

Avg. Score: 10.0/10

Winter offers the best overall diving conditions with calmer seas and better visibility, despite cooler temperatures.

Best Months for Siam Bay, Phuket in Thailand

January
Score: 10.0
February
Score: 10.0
March
Score: 10.0

Ideal Conditions for Siam Bay, Phuket in Thailand

Water Temp

Thermometer Emoji

27.2°C / 81.0°F

August

Visibility

Telescope Emoji

10.4m / 34.1ft

January

Wave Height

Wave Emoji

2.0m / 6.6ft

November

Wave Period

Wave Emoji

8.0s

January

Seasonal Insights for Siam Bay, Phuket in Thailand

Siam Bay, Phuket in Thailand shows typical northern hemisphere patterns with May being the warmest month (28.4°C) and December the coldest (23.0°C). The calmest conditions typically occur in November with average wave heights of 2.0m and wave periods of 8.0s. The most comfortable wave conditions are in November with a low wave steepness ratio, creating gentler swells. January offers the longest wave periods (8.0s), creating more comfortable and predictable conditions for boat entries and exits. Ocean currents are slowest in January (0.5m/s) and strongest in January (0.5m/s). January is usually the driest month with 0.1mm of precipitation. For beginners, the best time to visit would be during November to January, when ocean conditions are calmer with long-period waves and currents are typically weaker. Experienced divers might enjoy the challenges and potentially better visibility during the shoulder seasons, with moderate currents that can improve marine life encounters.

Scoring Legend:
9-10 (Excellent)
7-8 (Good)
5-6 (Average)
3-4 (Poor)
1-2 (Dangerous)

Last updated: 8 hr. ago - Jul 3, 2026

Note: This dive site is not a verified dive site. Please dive with caution. This dive site might have incorrect information by the community.

The closest dive destination to Siam Bay is Phuket

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Phuket

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