Oosekan Marine service started its service here at Osezaki for over 30 years.Mr. Yasuda, the owner of Oosekan (Accommodation) and Oosekan Marine Service, with the passion to introduce this special diving area to the whole of Japan, worked hard to make Osezaki into one the best diving area in the whole of Japan.

Now Oosekan Marine service with joint effort with NPO Japan Diving Experience would like to introduce this special diving destination.Oosekan Marine Service is located right in from of the Inner Bay. You can gear up and walk 30m to the entry point. The Service Supervisor Mr. Kumagai, although still young, has extensive knowledge and skills of guide you to the rare macro world of Osezaki. With his professional team of guides, they will surely make your visit here a worthwhile experience.

After each dive, you can jump into the hot tub with your wet/Dry suite to warm yourself quickly or take a hot shower located in the service. *Hot tub prepared during weekends during the autumn to spring months.Due to high demands by amateur and professional underwater photographers, camera related facilities offered here are extensive.

Due to the traditional style accommodation offered at Oosekan, you can enjoy the both diving and accommodation with the dive accommodation package offered. The dinner package offers delicious seafood Japanese dishes, including “sashimi” of the freshly prepared local fishes.

Opening hours: 08:00-17:00 (Saturday/Sunday/Public Holidays Open from 06:30)  ※On Night diving operating day Open to 21:30)

【Note from NPO】
On the day of Diving, the Diving Shop will have limited English available.
 But please don't be alarmed. NPO will assist regarding prior questions and enquiry for your booking. We will advise you how your diving will be on the day. The Guide will communicate with you using translation application on land and during your dive, sign language with will be reviewed before your dive.

Booking & Pay Method

  • Cash
  • Booking through NPO Japan Diving Experience

Booking Information

The booking will be done through NPO Japan Diving Experience. NPO Japan Diving Experience will try to clarify your concerns before your diving trip.

Shop Details

Shop Rules

Diving Information
1) The closest diving location is only 1min away from the Service. You are required to suit up and be ready to dive when diving in the inner bay. When diving at the other points, the guide will advise you to load up your gear (BCD/Regulator/ Mask&Snokel/ Fin/ Weights and camera (if you have them) on to a steel trolley.
2) (For diving location other than the inner bay) You and your guide will push the steel trolley to the diving spot, which will be a 10min-15minute walk)
3) The diving time is about 40min-45min with compulsory 5m 3min safety stop. (Tit will depend on your party’s air consumption)
* (Note: For safety reason, you may be required to finish diving early and without your safety stop. Please strictly follow your guides lead)
4) Depending on the wind and tide conditions on the day of diving, diving may be cancelled on the day or before your booked diving date. Please note that there will be no other options offered to you. The weather conditions in the winter season may be unpredictable.

5) After Diving, there will be a log writing session with your guide, looking back on what marine creatures you encountered.

6) Payment will be settled at the end of the day.

【Note from NPO】
Diving in Japan, like other diving service around the globe, require you to fill out a "Medical form" before diving. Refusing to do this, you may not be allowed to dive due to safety precautions.
NPO Japan Diving Experience advises you to proactively fill out the form linked from below.
It is a Medical Statement provided by The World Recreational Scuba Training Council (WRSTC).

Link to RSTC Medical form


Diving Fee

1Tank Guide Package 6,200JPY (Not including sales Tax) + Osezaki diving tax 350JPY/Day
2Tank Guide Package 9,400JPY (Not including sales Tax) + Osezaki diving tax 350JPY/Day
3Tank Guide Package 12,600JPY (Not including sales Tax) + Osezaki diving tax 350JPY/Day
1Tank Night Guide Package 6,800JPY (Not including sales Tax) + Osezaki diving tax 350JPY/Day
*for guests who purchased the Guide Package on the same day
(Accommodation Dive package)
1Night accommodation (Breakfast Dinner) + 4 tank Guide Package 23,500JPY (Not including sales Tax) + Osezaki diving tax 350JPY x 2
2Night accommodation (Breakfast Dinner) + 6 tank Guide Package 38,400JPY (Not including sales Tax) + Osezaki diving tax 350JPY x 3

Diving Information

※ Rental fee not included.
The diving fee may change without notice so please inquire NPO Japan Diving Experience for details.

Osezaki is very popular as a Buddy Diving area. Many local divers enjoy buddy diving with buddy diving rate. From language and safety concerns, Japan Diving Experience does not arrange buddy diving for guests.

Rental Fee

Full rental (including Wet Suite) 6,000 JPY *Rental boots size restricted to 21cm-30cm
Full rental (Including Dry suite and hood) 6,800JPY
BCD/Regulator rental 3,600JPY
BCD/Regulator + Wet suite rental 5,100JPY
BCD/Regulator + Dry suite rental 5,600JPY
BCD 2,000JPY
Regulator   2,000JPY
Wet suite  2,000JPY
Dry suite 3,000JPY
Hood Vest  600JPY
Ankle weight   200JPY
Weights (Per/1kg) 100JPY
Boots (size 21cm-30cm) 500JPY

Rental Information

*The price includes Tax
The rental fee may change without notice so please inquire NPO Japan Diving Experience for details.


Booking through NPO Japan Diving Experience