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Kozagawa River

This dive site offers freshwater river diving in the breathtaking Furuza River. Experience the incredible beauty of the clear waters as you explore the wonders beneath the surface. One of the main attractions here is the giant salamander, a special national natural monument, which can often be spotted in the upstream area, approximately an hour away from Furuza town.

In addition to the fascinating giant salamander, this dive site boasts a rich diversity of aquatic life. You'll have the opportunity to encounter various stream fish, including amago, eels, ayu, catfish, and unique species such as warts and mole fish. Keep an eye out for crustaceans like mole crabs and shrimps, as well as amphibians like the red-bellied newt. Freshwater insects like goatfish and kingfish add to the vibrant ecosystem.

Explore the depths of the Furuza River, which offers a variety of diving spots ranging from 3 to 4 meters deep, with some areas reaching depths of approximately 8 meters. This allows both intermediate and experienced divers to indulge in an unforgettable underwater adventure.

Located in Nukumi, Kozagawa, Higashimuro County, Wakayama Prefecture, Japan, this dive site provides fantastic underwater visibility of up to 8 meters. With a maximum depth of 9 meters, it is recommended for divers with advanced or expert-level skills. Dive enthusiasts can also take advantage of the proximity to the Koza River and the stunning Koza sea, enjoying the ultimate diving experience in both freshwater and saltwater environments.

Discover the wonders of this remarkable dive site, immerse yourself in Japan's natural beauty, and create unforgettable memories in the Furuza River.

Diving Conditions Score for Kozagawa River

6.9
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 Kozagawa River

Depth

9m

Visibility

8m

Experience Level

advanced
expert

Weather Conditions for Kozagawa River

Wave Height

1.42m

Wind Speed

7.2 m/s

Water Temp

24.6°C

Visibility

18.44km

Cloud Cover

78%

Wave Period

6.1s

Air Temperature

22.7°C

Precipitation

0.3 mm

Detailed 7-Day Diving Forecast for Kozagawa River
Alpha

Dive Score Chart for Kozagawa River

Best time to dive: 17:00 with score 6.478600000000001/10. Water conditions: Waves 1.42m, Wind 7.2 m/s.Best night dive time: 20:00 with score 6.275899999999999/10.

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

Sunrise at Kozagawa River: 06:00
Sunset at Kozagawa River: 18:00

Optimal diving conditions at Kozagawa River 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
17:00

Score: 6.5/10
Waves: 1.42m (6.1s), Wind: 7.2 m/s

🌙
Best Night
20:00

Score: 6.3/10
Waves: 1.3m, Wind: 5.4 m/s

Seasonal Analysis for Kozagawa River
Alpha

Historical patterns and best seasons for diving at Kozagawa River

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 Kozagawa River

Winter

Avg. Score: 8.7/10

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

Best Months for Kozagawa River

January
Score: 8.9
December
Score: 8.7
February
Score: 8.5

Ideal Conditions for Kozagawa River

Water Temp

Thermometer Emoji

26.5°C / 79.7°F

August

Visibility

Telescope Emoji

14.4m / 47.2ft

November

Wave Height

Wave Emoji

1.2m / 3.9ft

January

Wave Period

Wave Emoji

8.0s

January

Seasonal Insights for Kozagawa River

Kozagawa River shows typical northern hemisphere patterns with August being the warmest month (26.5°C) and January the coldest (3.3°C). The calmest conditions typically occur in January with average wave heights of 1.2m 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.

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

Last updated: 1 min. ago - Jun 21, 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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