Boulder City, Koh Similan in Thailand
Discover the breathtaking underwater city adorned with colossal and peculiar boulders. Delight in the enchanting stream shadows effortlessly found, leading you along a mooring-line to a maximum depth of 18m. Immerse yourself in a world where giant gorgonians, rays, sharks, sea needles, angelfish, nudibranchs, barracudas, tunas, and more grace the waters with their presence.
Prepare to be captivated by the awe-inspiring beauty of the expansive sea fan corals that await at 25-30m below the surface. As you explore the deeper realms, encountering stingrays and sharks becomes a thrilling possibility. Be amazed by the diversity of marine life, from ghost pipefish to various pipefish species. And if you possess a keen eye, you might even spot the elusive frogfish!
Situated in the mesmerizing Shark Fin Reef of Phang-nga Province, Thailand, this extraordinary dive site is perfect for both beginner and advanced divers. With a visibility of 16m and a maximum depth of 24m, it guarantees an unforgettable underwater adventure. Explore this remarkable destination and let its natural wonders leave you in awe.
Prepare to be captivated by the awe-inspiring beauty of the expansive sea fan corals that await at 25-30m below the surface. As you explore the deeper realms, encountering stingrays and sharks becomes a thrilling possibility. Be amazed by the diversity of marine life, from ghost pipefish to various pipefish species. And if you possess a keen eye, you might even spot the elusive frogfish!
Situated in the mesmerizing Shark Fin Reef of Phang-nga Province, Thailand, this extraordinary dive site is perfect for both beginner and advanced divers. With a visibility of 16m and a maximum depth of 24m, it guarantees an unforgettable underwater adventure. Explore this remarkable destination and let its natural wonders leave you in awe.
Diving Conditions Score for Boulder City, Koh Similan in Thailand
6.9
Above AverageDecent conditions, proceed with caution.
The score is based on a calculation of the current weather and sea conditions.
Dive Site Overview for Boulder City, Koh Similan in Thailand
Depth
24m
Visibility
16m
Experience Level
beginner
advanced
Weather Conditions for Boulder City, Koh Similan in Thailand
Wave Height
0.52m
Wind Speed
12.8 m/s
Water Temp
30.4°C
Visibility
19.38km
Cloud Cover
66%
Wave Period
6.9s
Air Temperature
30°C
Precipitation
2.9 mm
Detailed 7-Day Diving Forecast for Boulder City
Alpha
Dive Score Chart for Boulder City
Best time to dive: 16:00 with score 8.207195035460995/10. Water conditions: Waves 0.54m, Wind 6.8 m/s.Best night dive time: 5:00 with score 8.360299176954733/10.
Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.
Sunrise at Boulder City: 06:00
Sunset at Boulder City: 18:00
Optimal diving conditions at Boulder City 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
5:00Score: 8.4/10
Waves: 0.46m (8.1s), Wind: 1.7 m/s
Safest Overall
16:00Score: 8.2/10
Waves: 0.54m (7.05s), Wind: 6.8 m/s
Best Day
16:00Score: 8.2/10
Waves: 0.54m, Wind: 6.8 m/s
Seasonal Analysis for Boulder City, Koh Similan in ThailandAlpha
Historical patterns and best seasons for diving at Boulder City, Koh Similan 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 Boulder City, Koh Similan 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 Boulder City, Koh Similan in Thailand
January
Score: 10.0
February
Score: 10.0
March
Score: 10.0
Ideal Conditions for Boulder City, Koh Similan in Thailand
Water Temp
27.0°C / 80.6°F
August
Visibility
11.0m / 36.1ft
January
Wave Height
1.6m / 5.2ft
April
Wave Period
8.0s
January
Seasonal Insights for Boulder City, Koh Similan in Thailand
Boulder City, Koh Similan in Thailand shows typical northern hemisphere patterns with May being the warmest month (28.1°C) and December the coldest (23.1°C). The calmest conditions typically occur in April with average wave heights of 1.6m and wave periods of 8.0s. The most comfortable wave conditions are in April 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 0.2mm of precipitation. For beginners, the best time to visit would be during April to June, 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.
Last updated: 1 min. ago - Jun 19, 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 Boulder City is Koh Similan
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