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Hasama Ocean Park

Located on the beautiful Boso Peninsula in Japan, Hasama Ocean Park is a premier dive site nestled in the inner bay of Tateyama. While the park boasts a picturesque beach, the real excitement lies in the exhilarating boat diving experiences it offers. Just a quick five-minute boat ride from the harbor, you'll find the renowned "Takane" point, featuring a mesmerizing underwater shrine adorned with a magnificent torii.

Immerse yourself in a vibrant underwater world brimming with life. Be captivated by the kaleidoscope of colorful fish dancing among bustling soft corals. Keep an eye out for fascinating creatures like lobsters, nudibranchs, and captivating frogfish. The underwater shrine not only provides a visual treat but also holds historical significance as an integral part of a genuine above-water shrine. Nearby, an extraordinary underwater air dome awaits, offering a unique opportunity to resurface beneath the waves.

For the more adventurous divers, Hasama Ocean Park offers vast cave systems near the harbor, thriving with an array of fascinating marine species. During the summer months, lucky visitors may even catch a glimpse of the magnificent sunfish (mola mola) and, on rare occasions, even the majestic whale sharks.

With excellent visibility reaching up to 10 meters and a maximum depth of 14 meters, Hasama Ocean Park is an ideal diving destination for divers of all levels, from beginners to advanced. Explore the wonders beneath the surface and discover the secrets this underwater paradise has to offer.

Plan your next diving adventure at Hasama Ocean Park in Hasama, Tateyama, Chiba Prefecture, Japan.

Diving Conditions Score for Hasama Ocean Park

7
Good

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

Dive Site Overview for Hasama Ocean Park

Depth

14m

Visibility

10m

Experience Level

beginner
advanced

Weather Conditions for Hasama Ocean Park

Wave Height

0.92m

Wind Speed

6.5 m/s

Water Temp

23.4°C

Visibility

6.62km

Cloud Cover

64%

Wave Period

7.25s

Air Temperature

23.6°C

Precipitation

0 mm

Detailed 7-Day Diving Forecast for Hasama Ocean Park
Alpha

Dive Score Chart for Hasama Ocean Park

Best time to dive: 6:00 with score 7.589213793103449/10. Water conditions: Waves 0.9m, Wind 6.2 m/s.Best night dive time: 19:00 with score 6.94438559670782/10.

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

Sunrise at Hasama Ocean Park: 06:00
Sunset at Hasama Ocean Park: 18:00

Optimal diving conditions at Hasama Ocean Park 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
6:00

Score: 7.6/10
Waves: 0.9m (7.25s), Wind: 6.2 m/s

🌞
Safest Overall
13:00

Score: 7.5/10
Waves: 0.82m (7.45s), Wind: 6 m/s

🌙
Best Night
19:00

Score: 6.9/10
Waves: 0.76m, Wind: 7.9 m/s

Seasonal Analysis for Hasama Ocean Park
Alpha

Historical patterns and best seasons for diving at Hasama Ocean Park

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 Hasama Ocean Park

Winter

Avg. Score: 8.4/10

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

Best Months for Hasama Ocean Park

January
Score: 8.5
December
Score: 8.4
February
Score: 8.3

Ideal Conditions for Hasama Ocean Park

Water Temp

Thermometer Emoji

25.6°C / 78.1°F

August

Visibility

Telescope Emoji

12.0m / 39.4ft

October

Wave Height

Wave Emoji

2.0m / 6.6ft

November

Wave Period

Wave Emoji

8.0s

January

Seasonal Insights for Hasama Ocean Park

Hasama Ocean Park shows typical northern hemisphere patterns with August being the warmest month (25.6°C) and January the coldest (3.3°C). The calmest conditions typically occur in November with average wave heights of 2.0m and wave periods of 8.0s. The most comfortable wave conditions are in November 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 November to January, 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 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.

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