San Francisco Maru, Truk Lagoon
The San Francisco Maru, a 117-meter-long passenger-cargo ship constructed in 1919, was deliberately sunk during operation Hailstone in 1944. This remarkable wreck, resting on an even keel between 42 and 64 meters, lies in the depths of the majestic Truk Lagoon. Loaded with war materials, it stands as one of the most captivating technical wreck dive sites in this region of the Federated States of Micronesia.
Similar to the other wrecks in Truk Lagoon, the San Francisco Maru is adorned with an extensive array of hard and soft corals, showcasing vibrant colors and hosting a diverse range of marine life. Exploring the hidden wonders of this underwater sanctuary is an unforgettable experience for advanced and expert divers alike.
With visibility of up to 17 meters and a maximum depth of 49 meters, this dive site provides a thrilling adventure for those seeking an extraordinary underwater exploration. Located near Chuuk, Federated States of Micronesia, the San Francisco Maru offers divers a chance to delve into the rich history and natural beauty of this breathtaking destination.
Similar to the other wrecks in Truk Lagoon, the San Francisco Maru is adorned with an extensive array of hard and soft corals, showcasing vibrant colors and hosting a diverse range of marine life. Exploring the hidden wonders of this underwater sanctuary is an unforgettable experience for advanced and expert divers alike.
With visibility of up to 17 meters and a maximum depth of 49 meters, this dive site provides a thrilling adventure for those seeking an extraordinary underwater exploration. Located near Chuuk, Federated States of Micronesia, the San Francisco Maru offers divers a chance to delve into the rich history and natural beauty of this breathtaking destination.
Diving Conditions Score for San Francisco Maru, Truk Lagoon
7.4
GoodGood diving conditions!
The score is based on a calculation of the current weather and sea conditions.
Dive Site Overview for San Francisco Maru, Truk Lagoon
Depth
49m
Visibility
17m
Experience Level
advanced
expert
Weather Conditions for San Francisco Maru, Truk Lagoon
Wave Height
1m
Wind Speed
15.4 m/s
Water Temp
30.1°C
Visibility
39.08km
Cloud Cover
100%
Wave Period
6.55s
Air Temperature
26.7°C
Precipitation
0.1 mm
Detailed 7-Day Diving Forecast for San Francisco Maru, Truk Lagoon
Alpha
Dive Score Chart for San Francisco Maru, Truk Lagoon
Best time to dive: 16:00 with score 7.716587591240876/10. Water conditions: Waves 0.9m, Wind 16.4 m/s.Best night dive time: 19:00 with score 7.2692154589371984/10.
Chart showing hourly dive conditions including wave height, wind speed, water temperature, and visibility throughout the day.
Sunrise at San Francisco Maru, Truk Lagoon: 06:00
Sunset at San Francisco Maru, Truk Lagoon: 18:00
Optimal diving conditions at San Francisco Maru, Truk Lagoon 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
16:00Score: 7.7/10
Waves: 0.9m (6.85s), Wind: 16.4 m/s
Safest Overall
17:00Score: 7.7/10
Waves: 0.88m (6.85s), Wind: 16.9 m/s
Best Night
19:00Score: 7.3/10
Waves: 0.86m, Wind: 15.5 m/s
Seasonal Analysis for San Francisco Maru, Truk LagoonAlpha
Historical patterns and best seasons for diving at San Francisco Maru, Truk Lagoon
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 San Francisco Maru, Truk Lagoon
Winter
Avg. Score: 9.4/10
Winter offers the best overall diving conditions with calmer seas and better visibility, despite cooler temperatures.
Best Months for San Francisco Maru, Truk Lagoon
January
Score: 9.6
February
Score: 9.5
December
Score: 9.2
Ideal Conditions for San Francisco Maru, Truk Lagoon
Water Temp
27.0°C / 80.6°F
July
Visibility
10.0m / 32.8ft
January
Wave Height
2.1m / 6.9ft
September
Wave Period
8.0s
January
Seasonal Insights for San Francisco Maru, Truk Lagoon
San Francisco Maru, Truk Lagoon shows typical northern hemisphere patterns with June being the warmest month (27.2°C) and December the coldest (23.9°C). The calmest conditions typically occur in September with average wave heights of 2.1m and wave periods of 8.0s. The most comfortable wave conditions are in September 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 0.5mm of precipitation. For beginners, the best time to visit would be during September to November, 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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