| 1906 |
Founded by Nakanosuke Seki, the great-grandfather of the current president, at the current Iwaya Head Office address. Starts the Cargo shipping and diving business under the name of Seki Shipping with a diving boat and a cargo ship. |
| 1930 |
The founder, Nakanosuke Seki, passes away. Yoshio Seki, the grandfather of the current president inherits the family business and renames the company SEKIKAIJI Industry. |
| 1943 |
Establishes a department for automobile shipping transportation between the mainland and Awaji Island, primarily between Akashi and Iwaya. |
| 1944 |
Begins collaboration with the Kansai Electric Power Co., Inc.’s Kobe and Himeji Branches, engaging in pioneering submarine cable laying activities across the Akashi Strait (between the mainland and Awaji Island and between Himeji and Ie Island). Since then, the company has been recognized by power companies and cable manufacturers for its exceptional specialized skills, leading to its involvement in associated repairs and protective works related to submarine cable laying. |
| 1946 |
Begins newspaper delivery business commissioned by newspaper publishers, transporting newspapers from the mainland to all over Awaji Island. |
| 1948 |
Receives approval from the Kobe Maritime Safety Agency to commence vessel rescue operations, becoming an officially recognized service provider. |
| 1950 |
The Akashi Contact Office opens at 38 Nishi-Honmachi, Akashi. |
| 1952 |
Engages in the wooden ship transportation business under the Kobe Maritime Bureau (Registration No. 907). |
| 1954 |
The Warehouse Operation Office opens at 1414-2 Iwaya, Awaji. The Department of Automobile Shipping Transportation closes due to the opening of the Japan Highway Public Corporation’s Ferryboat between Akashi and Iwaya. |
| 1955 |
Engages in the installation of the underwater equipment for the Japan Maritime Self-Defense Force’s Kariya Magnetic Measurement Station and has become the approved bidder ever since. |
| 1958 |
Yoshio Seki passes away. Mamoru Seki, the father of the current president, becomes the president. |
| 1963 |
Involves in the construction of the boring tower for a geological survey of Akashi Strait–Honshu–Shikoku Bridge construction. |
| 1966 |
Undertakes improvements in facilities and the mechanization and rationalization of the company due to an increase in construction works and demands. Reorganizes the company and renames it SEKIKAIJI Industry CO., LTD. Set the coasts of Honshu, Shikoku, Kyushu, and Okinawa as the main operation area ever since. |
| 1967 |
Enters the submarine cable installation business in earnest. Pioneers in the industry by completing and launching the self-navigating, dedicated cable-laying vessel “Seki Maru No.18.” |
| 1968 |
Becomes involved in repairing the No. 2 submarine cable between the Mainland and Awaji Island, frequently damaged by vessel anchors in strong currents. The company earns high praise for its rapid response. |
| 1970 |
Engages in the installation of a submarine cable across the Akashi Strait. Constructs company-owned housing to improve the working environment for employees. |
| 1973 |
Launches the cable-laying barge “Awaji” |
| 1976 |
Establishment of a materials warehouse at Matsuho, Awaji-cho, Tsuna-gun. |
| 1978 |
Becomes an official bidder approved by the 5th Regional Coast Guard. |
| 1985 |
Encourages obtaining qualifications for construction work, aiming to expand the business scope beyond maritime services. |
| 1988 |
Launches “Awashima.” Begins Akashi Strait submarine cable patrol operation on the guard boat “Awashima.” |
| 1991 |
Launches the cable-laying barge “Awaji 2” to participate in the project to install a submarine water pipeline in Oyano, Kumamoto Prefecture. |
| 1991 |
Equips “Awaji 2” with a turntable to accommodate large-diameter cable-laying projects and prepares for larger-scale and more complex construction tasks. |
| 1993 |
Engages in the installation of power and industrial water supply cables for the Tokyo Bay Aqualine construction works.The method used is simultaneous laying and burial with a chain cutter burial machine. |
| 1994 |
Launches the state-of-the-art tug and operation vessel “Seki Maru No. 8,” equipped with various specialized equipment and featuring high maneuverability. |
| 1996 |
Celebrates the 30th anniversary of its incorporation and the 90th anniversary of its founding. |
| 1996 |
Extends “Awaji 2” from 47 m to 60 m. |
| 1997 |
Upgrades the turntable on “Awaji 2” from 500 tons to 700 tons in response to large-scale construction project demands. |
| 2004 |
Masaru Seki is appointed as president and Mamoru Seki as chairman. |
| 2005 |
Starts the dynamic positioning (DP) conversion of the cable-laying barge “Awaji 2,” renaming it to “Awaji.” In order to accommodate modern construction requirements, the vessel is expanded in width from 18 m to 23 m and equipped with the latest navigation systems, aiming to expand business outreach. |
| 2006 |
Celebrates the 40th anniversary of its incorporation and the 100th anniversary of its founding. Completes the multipurpose fiberglass-reinforced plastic (FRP) boat “Manta” (with a main engine horsepower of 170 PS and equipped with a bow thruster). |
| 2008 |
Completes the tug and work vessel “Seki Maru No. 8” (19-ton class) with a main engine horsepower of 1,300 PS and equipped with a 10-ton winch at the bow. |
| 2008 |
Launches and operates its own brand of burial machine (water jet type), engaging in simultaneous laying and burial with a drilling depth of two meters and DPS control over a distance of 16,122 meters. |
| 2009 |
Introduces an ROV (underwater TV robot). |
| 2009 |
Receives a large overseas construction order (between Jindo and Jejudo, South Korea) for the HVDC link construction (rock berm installation) between Jindo & Jejudo. |
| 2010 |
Establishes the Project Propulsion Department. |
| 2010 |
Purchases 1,050 square meters of industrial land in the Tsuna-Ikuho area (sold by the Hyogo Prefectural Enterprise Agency). |
| 2011 |
Celebrates the 45th anniversary of its incorporation and the 105th anniversary of its founding. |
| 2011 |
Begins construction work in South Korea on the rock berm installation. |
| 2012 |
Completes the construction work in South Korea on the rock berm installation. |
| 2013 |
多目的DPS作業台船『あさひ』竣工 |
| 2013 |
Completes the multipurpose DPS work barge “Asahi.” |
| 2014 |
津名生穂地区産業用地（兵庫県企業庁）175平米追加購入（合計1225平米） |
| 2014 |
津名港艤装岸壁近傍に倉庫、津名DEPOT建設/竣工（システム建築 延床面積452.66平米） |
| 2014 |
移動式天井クレーン2.8トン吊設備 海洋設備メンテナンス／試験用水槽（3×4×深さ2ｍ）設備 |
| 2014 |
更衣室（男女別、シャワールーム付）設備 |
| 2014 |
Purchases an additional 175 square meters of industrial land in the Tsuna-Ikuho area (sold by the Hyogo Prefectural Enterprise Agency), totaling 1,225 square meters. |
| 2014 |
Constructs and completes the Tsuna Depot (a warehouse of system construction with a total floor area of 452.66 square meters) near the Tsuna port fitting wharf, featuring a mobile ceiling crane with a 2.8-ton lifting capacity, a two-meter-deep marine equipment maintenance/testing water tank (3×4 m in area), and changing rooms (separate for men and women, with showers). |
| 2016 |
創立50周年、創業110周年を迎える |
| 2016 |
ROV（水中テレビロボ）2台目導入 |
| 2016 |
津名生穂地区産業用地（兵庫県企業庁）2526.22平米追加購入（合計3751.22平米） |
| 2016 |
Celebrates the 50th anniversary of its incorporation and the 110th anniversary of its founding. |
| 2016 |
Introduces a second ROV (underwater TV robot). |
| 2016 |
Purchases an additional 2,526.22 square meters of industrial land in the Tsuna-Ikuho area (sold by the Hyogo Prefectural Enterprise Agency), totaling 3,751.22 square meters. |
| 2017 |
新生DPS台船『あわじ』竣工（1,500t型ターンテーブル搭載） |
| 2017 |
『旧あわじ』は700tターンテーブルを既存のまま使用し 船名を『あかり』に変更 |
| 2017 |
※あかりDPS装置非搭載 |
| 2017 |
Completes the new DPS barge “Awaji” equipped with a 1,500-ton turntable. |
| 2017 |
The old “Awaji” continues to use the 700-ton turntable and is renamed “Akari.” |
| 2020 |
『あさひ』1,260t型ターンテーブル搭載 |
| 2020 |
ROV（水中テレビロボ）3台目導入 |
| 2020 |
Equips “Asahi” with a 1,260-ton turntable. |
| 2020 |
Introduces a third ROV (Underwater TV Robot). |
| 2021 |
秋田能代洋上風力海底ケーブル設置工事完工 |
| 2021 |
創立55周年、創業115周年を迎える |
| 2021 |
津名生穂地区産業用地（兵庫県企業庁）1608.11平米追加購入（合計5359.33平米） |
| 2021 |
Completes the submarine cable installation work for the Akita Noshiro offshore wind farm. |
| 2021 |
Celebrates the 55th anniversary of its incorporation and the 115th anniversary of its founding. |
| 2021 |
Purchases an additional 1,608.11 square meters of industrial land in the Tsuna-Seiho area (sold by the Hyogo Prefectural Enterprise Agency), totaling 5,359.33 square meters. |
| 2022 |
グループ会社「株式会社 関仲」設立 |
| 2022 |
Establishes the group company SEKINAKA CO., LTD. |
| 2023 |
石狩湾新港洋上風力海底ケーブル敷設工事完工 |
| 2023 |
Completion of the Ishikari Bay New Port Offshore Wind Farm subsea cable installation project. |
| 2024 |
海底ケーブル建設工事（敷設・撤去・修理など）を目的とした、新たなDPS台船の建造を決定 |
| 2024 |
Decision made to construct a new DPS barge for subsea cable construction work, including installation, removal, and repair. |
| 2025 |
本社を岩屋から津名DEPOT内に移転し、津名本社として営業を開始（旧本社は岩屋本店として継続） |
| 2025 |
Headquarters relocated from Iwaya to Tsunadepot, beginning operations as the new Tsuna Headquarters (the former Headquarters in Iwaya will continue to operate as the Iwaya Head Office). |
