Challenging the
hidden depths
of the oceans


Logo team kuroshio@2x

CITIZEN WATCH CO., LTD. (under the contractual name PROMASTER) is the prime sponsor and official supplier backing the work of Team KUROSHIO, an underwater exploration team from Japan. Team KUROSHIO is tackling the Shell Ocean Discovery XPRIZE*1, a competition to deliver technologies for rapid, wide area mapping of the sea floor. Since its debut in 1989, CITIZEN’s PROMASTER sports watch brand has exhibited outstanding levels of functionality, durability and safety in even the harshest environments. No wonder then that PROMASTER has won supporters worldwide as a watch that stirs the imagination and desire of explorers to take on the unknown. With “GO BEYOND”*2 as PROMASTER’s key message, our support of Team KUROSHIO as they face the unknown is deeply in synch with the PROMASTER brand.



Designed in collaboration with Team KUROSHIO, the model base is a diver’s watch with a built-in depth metre. Featuring blue reminiscent of the deep sea as a baseline colour, the model adopts orange as an accent colour in honor of the team’s autonomous underwater vehicle (AUV). Only 1,000 of these watches exist, with each sold in a limited-edition box and with an engraved case back commemorating the collaboration.


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Product details
  • LIMITED 1,000
AUV AU2000e(Institute of Industrial Science, The University of Tokyo)
Commemorative engravement
Includes limited-edition box


Supporting the mission of Team KUROSHIO,
a Japanese underwater exploration team
involved in the global XPRIZE competition


Team KUROSHIO is an eight-organization joint research team tackling the Shell Ocean Discovery XPRIZE*1, a competition to deliver technologies for rapid, wide area mapping of the sea floor. Team members hail from the Japan Agency for Marine-Earth Science and Technology, The University of Tokyo, Kyushu Institute of Technology, the National Institute of Maritime, Port and Aviation Technology, Mitsui E&S Shipbuilding Co., Ltd., Nippon Marine Enterprises, Ltd., KDDI Research, Inc., and Yamaha Motor Co., Ltd. Using only robotic systems (AUVs/ASVs)* at a depth of 4,000 metres, and with no mothership support, participants in the competition must survey a vast area of more than 250 km2 in under 24 hours. Once complete, they must then produce images of 10 locations indicated on a nautical chart within 48 hours. Spanning roughly three years, the competition has a trio of major hurdles participants must overcome to continue. Team KUROSHIO is the only Japanese team to clear two hurdles - the technology proposal screening stage and the Round 1 technology evaluation test. Having survived to become one of only nine teams to advance to the final round, Team KUROSHIO is gearing up to take on the final hurdle – the actual sea floor mapping competition in Round 2, scheduled to take place between November and December 2018. Through this epic competition, with prizes now totaling $7 million at stake, Team KUROSHIO is helping trigger a dramatic leap in underwater and sea floor exploration technology, a step that is opening the door to new underwater discoveries and a new future.

*AUV: Autonomous Underwater Vehicle ASV: Autonomous Surface Vehicle

$7M Shell Ocean Discovery XPRIZE

Along with supporting the work of underwater exploration team “Team KUROSHIO” as the prime sponsor, CITIZEN (under the contractual name PROMASTER) provides the team with diver's watches, including the PROMASTER Eco-Drive*3 Professional Diver 1000m, as the team’s official supplier.

  • *1 XPRIZE Managed by the XPRIZE Foundation, a non-profit organization established in 1995, the XPRIZE is a global competition committed to finding solutions to some of the world’s most pressing concerns. Themes for the competition centre around five fields: learning, exploration, energy and environment, global-scale development and life sciences.
  • *2 PROMASTER key message “GO BEYOND.” Three Values of PROMASTER Functionality: Develop and equip watches with revolutionary technology, driven by dedication to helping humanity venture into the unknown. When spec performance initially appears excessive, consider it critical to spurring the imagination of those challenging their own limits. Durability: Bring high visibility and waterproofing, shock resistance, abrasion resistance and other features together to deliver world-best levels of durability, capable of withstanding the harshest environments. Safety: Through safety features that fully consider the user, PROMASTER owners can enjoy the full benefit of their watches no matter the challenge or location.
  • *3 Eco-Drive is CITIZEN’s proprietary technology that powers watches using any natural or artificial light source, eliminating the need to replace batteries. Certified as an Eco Mark product for the first time in the watch industry.