Boulder Alley
This dive site in the United States offers a fantastic night diving experience with exceptionally clear water. Discover the beauty of the underwater world as you drift along the captivating cliff line between the Navy sea wall and Shark's Pit. Prepare to be amazed by the abundance of pyramid butterfly fish swimming in large schools, accompanied by the occasional Pelagic creature. The west-end of this drift dive is particularly popular for spotting a large school of Pyramid Butterfly Fish. Additionally, turtles are frequently encountered on dives here. With a visibility of 21m and a maximum depth of 22m, this dive is suitable for both beginner and advanced divers. Located at Haputo Road, Sånta Rita-Sumai Municipality, Guam, 96915, United States, this dive location provides a remarkable experience for divers of all skill levels.
Diving Conditions Score for Boulder Alley
6.8
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 Alley
Depth
22m
Visibility
21m
Experience Level
beginner
advanced
Weather Conditions for Boulder Alley
Wave Height
0.96m
Wind Speed
21.5 m/s
Water Temp
29.8°C
Visibility
6.98km
Cloud Cover
30%
Wave Period
7.25s
Air Temperature
27°C
Precipitation
0.1 mm
Detailed 7-Day Diving Forecast for Boulder Alley
Alpha
Dive Score Chart for Boulder Alley
Best time to dive: 8:00 with score 7.575933333333333/10. Water conditions: Waves 1.02m, Wind 5.6 m/s.Best night dive time: 1:00 with score 6.980319298245614/10.
Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.
Sunrise at Boulder Alley: 06:00
Sunset at Boulder Alley: 18:00
Optimal diving conditions at Boulder Alley 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
8:00Score: 7.6/10
Waves: 1.02m (7.5s), Wind: 5.6 m/s
Best Night
1:00Score: 7.0/10
Waves: 1.04m, Wind: 7.2 m/s
Seasonal Analysis for Boulder AlleyAlpha
Historical patterns and best seasons for diving at Boulder Alley
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 Alley
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 Alley
January
Score: 10.0
February
Score: 10.0
March
Score: 10.0
Ideal Conditions for Boulder Alley
Water Temp
21.3°C / 70.3°F
June
Visibility
20.1m / 65.9ft
May
Wave Height
0.2m / 0.7ft
January
Wave Period
8.0s
January
Seasonal Insights for Boulder Alley
Boulder Alley shows typical northern hemisphere patterns with June being the warmest month (21.3°C) and December the coldest (17.3°C). The calmest conditions typically occur in January with average wave heights of 0.2m and wave periods of 8.0s. The most comfortable wave conditions are in January 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 0.0mm of precipitation. For beginners, the best time to visit would be during January to March, 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 22, 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.
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