Introduction to the Founder of DIVE Explorers and Japan Karst & Underwater Exploraton Project

Yoshitaka Isaji, Underwater Explorer in Japan

Underwater Explorer
YoshitakaIsaji

伊左治 佳孝

Exploring uncharted underwater environments as my life’s work, I conduct a wide range of expeditions into unexplored areas—underwater caves, deep wrecks, and mines—while also actively joining overseas projects and building a worldwide community.
Today, alongside underwater exploration, I also teach technical diving, sharing real-world field experience that can only be gained through real explorations.

Yoshitaka Isaji, one of the most famous Underwater Explorer in Japan
Photos of places discovered/explored by an underwater explorer

Places Where Yoshitaka Isaji Has Conducted Exploration and Underwater Surveying

Exploring a subterranean lake / underwater cave on South Daito Island

南大東島

South Daito Island

A remote island in the open sea—South Daito Island.
Many underwater limestone caves remain here that no one has ever explored, and we work in cooperation with the local community to investigate and open up these sites.
Because red soil accumulates underwater, the environment becomes extremely silty and hazardous with ease; however, breathtaking scenery that no one has ever seen spreads out within these caves.

Doing investigation at the submerged Chousei Coal Mine

長生炭鉱

Chousei Coal Mine

Chousei Coal Mine in Ube City, Yamaguchi Prefecture, was a coal mine that operated until World War II. Because the mine extended beneath the seabed, it suffered a collapse and flooding of the tunnels, resulting in the deaths of 183 people.
Until now, recovering remains has been considered impossible; however, by applying the knowledge and techniques of an underwater explorer, we are working toward locating human remains.

Project

I lead an exploration and survey project called JKUEP.
JKUEP stands for Japan Karst & Underwater Exploration Project, and it conducts exploration and investigation of Japan’s unexplored underwater caves, submerged mines, shipwrecks, and more.

Japan Karst & Underwater Exploration Project

Media/press coverage collage

Science ZERO key visual / still

NHK サイエンスZERO

NHK science ZERO

Focusing on the “science” aspect of South Daito Island, deeper and more scientific research based on our past investigations was featured in an educational science program.

NHK Special still / underwater survey scene

NHK スペシャル

NHK Special

HK Special featured the exploration of underwater limestone caves on South Daito Island and investigations into newly discovered organisms, carried out by a team of explorers from around the world led by Yoshitaka Isaji.
Most underwater filming was conducted using 8K cameras, and the project also employed cutting-edge technologies such as photogrammetry in underwater limestone caves.

Frontier still

NHK フロンティア

NHK BS Frontier

The investigation and exploration of beautiful underwater limestone caves hidden beneath South Daito Island, Okinawa, were featured on NHK BS program “Frontier.”

NNN Document still

Nippon News Network Document

NNN Document

The program “NNN Document: Aboji ga Nemuru Umi” featured the efforts involved in the diving exploration at Chousei Coal Mine.

TBS feature still

TBS JAPAN NEWS NETWORK

Hodo Tokushu (News Feature)

TBS “Hodo Tokushu” featured Yoshitaka Isaji’s work as an underwater explorer and technical diving instructor, including the diving exploration at Chousei Coal Mine.

News / Feature Programs, etc.


  • Ohayo Nippon (NHK)
  • Hodo Station (TV Asahi)
  • TBS NEWS (TBS)
  • KRY Yamaguchi Broadcasting
  • NTV NEWS
  • yab Yamaguchi Asahi Broadcasting
  • tys TV Yamaguchi
  • Mainichi Shimbun
  • Yomiuri Shimbun
  • Asahi Shimbun
  • Okinawa Times
  • Ryukyu Shimpo
  • Chunichi Shimbun
  • Choshu Journal
  • Shimbun Akahata
  • Tokyo Shimbun

And more—across various news outlets, newspapers, magazines, and columns.

Goals and Purpose as an Underwater Explorer

First Goal

Exploring the Unexplored

The desire to explore places no one has reached before is a fundamental human impulse.
Humanity spread across the world from its origins in Africa as a result of this impulse, and I believe that pursuing frontier exploration contributes to expanding the reach of human knowledge and activity.

Second Goal

Taking on Valuable Frontier Exploration

Rather than exploring only to satisfy my own intellectual curiosity, I also take on social activities in places that are otherwise unreachable without exploration skills.
Discovering new species at great depth, investigating subterranean groundwater systems, and even conducting rescue activities in overhead/closed environments—there are countless locations that are both valuable to investigate and impossible to reach without the techniques and knowledge we have gained.

Third Goal

Exploring Together with a Team

Underwater exploration cannot be done alone.
Everyone who supports our activities, helps us, and explores alongside us is part of our team. Tackling the unexplored as a team is highly rewarding—and meaningful.
My work as a technical diving instructor is also intended to develop future team members who can explore together. I look forward to seeing new team members emerge from among my students.

Technical Diving Instructor Qualifications

Based on experience gained through exploration and the communities formed through each project, I provide technical diving training and guiding.
If you seek a more exciting experience, want to explore underwater environments in the future, or want to dive at sites pioneered by an underwater explorer, please feel free to contact us.

Diving Instructor Certifications


TDI Instructor Certifications
  • TDI Full Cave Instructor
  • TDI Stage Cave Instructor
  • TDI Advanced Trimix Instructor
  • TDI Advanced Wreck Instructor
  • TDI Sidemount Instructor
  • TDI Technical DPV Instructor
  • TDI Advanced Gas Blender Instructor

PADI Tec Rec Instructor Certifications
  • PADI Tec Trimix Instructor
  • PADI Tec Sidemount Instructor
  • PADI Trimix Gas Blender Instructor
  • PADI IDC Staff Instructor
  • PADI Master Scuba Diver Trainer

IANTD Instructor Certifications
  • IANTD CCR Advanced Nitrox Instructor
  • IANTD CCR Trimix Instructor

Diver Certifications


IANTD Diver Certifications
  • IANTD CCR Cave Diver

GUE Diver Certifications
  • GUE Tech2 Diver
  • GUE CCR1 Diver
  • GUE Cave2 Diver
  • GUE Cave Sidemount Diver
  • GUE Cave DPV Diver
  • GUE Cave Survey Diver