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Mutsu (Wreck)

Katsura Island in Yamaguchi Prefecture, Japan is home to the sunken battleship of the Japanese Navy, making it a unique and captivating dive site. This historical wreck measures an impressive 224 meters in length and 34 meters in width, resting at a varying depth ranging from 40 meters to 10 meters.

Divers visiting this site are treated to more than just the wrecks. Throughout the year, an abundance of marine life including mackerel and yellowtail can also be encountered. As you explore the area, you'll discover remnants of the ship's bridge and bow sections that were salvaged in the past. However, the majority of the wreck remains intact, with its debris scattered across hundreds of meters on the seafloor. Keep an eye out for intriguing artifacts such as gun shells and machine gun shells nestled in the sandy bed.

With visibility ranging from 2 to 10 meters, divers have the opportunity to fully appreciate the beauty and history this site has to offer. Whether you are an experienced recreational diver or a skilled technical diver, this dive site caters to both levels of expertise.

Located near 柱島, Iwakuni, Yamaguchi Prefecture, Japan, this dive site provides a fascinating glimpse into Japan's naval history. With a maximum depth of 9 meters, it is essential for divers to possess expert skills to explore this relatively shallow but intricate underwater world.

Don't miss out on this exceptional dive experience in Japan's Seto Inland Sea. Prepare to be amazed by the sunken battleship and its surrounding marine life.

Diving Conditions Score for Mutsu (Wreck)

8.1
Very Good

Very good diving conditions!
The score is based on a calculation of the current weather and sea conditions.

Dive Site Overview for Mutsu (Wreck)

Depth

9m

Visibility

6m

Experience Level

expert

Weather Conditions for Mutsu (Wreck)

Wave Height

0.1m

Wind Speed

8.4 m/s

Water Temp

22.9°C

Visibility

20.26km

Cloud Cover

100%

Wave Period

3.85s

Air Temperature

21.6°C

Precipitation

0 mm

Detailed 7-Day Diving Forecast for Mutsu (Wreck)
Alpha

Dive Score Chart for Mutsu (Wreck)

Best time to dive: 15:00 with score 8.457365408805032/10. Water conditions: Waves 0.14m, Wind 5.8 m/s.Best night dive time: 22:00 with score 8.014289795918367/10.

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

Sunrise at Mutsu (Wreck): 06:00
Sunset at Mutsu (Wreck): 18:00

Optimal diving conditions at Mutsu (Wreck) 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
15:00

Score: 8.5/10
Waves: 0.14m (2.65s), Wind: 5.8 m/s

🌞
Safest Overall
9:00

Score: 8.4/10
Waves: 0.14m (2.65s), Wind: 5.4 m/s

🌙
Best Night
22:00

Score: 8.0/10
Waves: 0.08m, Wind: 8.4 m/s

Seasonal Analysis for Mutsu (Wreck)
Alpha

Historical patterns and best seasons for diving at Mutsu (Wreck)

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 Mutsu (Wreck)

Winter

Avg. Score: 8.9/10

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

Best Months for Mutsu (Wreck)

January
Score: 9.1
December
Score: 8.8
February
Score: 8.7

Ideal Conditions for Mutsu (Wreck)

Water Temp

Thermometer Emoji

27.0°C / 80.6°F

August

Visibility

Telescope Emoji

15.2m / 49.9ft

November

Wave Height

Wave Emoji

1.0m / 3.3ft

January

Wave Period

Wave Emoji

8.0s

January

Seasonal Insights for Mutsu (Wreck)

Mutsu (Wreck) shows typical northern hemisphere patterns with August being the warmest month (27.0°C) and February the coldest (2.5°C). The calmest conditions typically occur in January with average wave heights of 1.0m 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.

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

Last updated: 1 min. ago - Jun 17, 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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