InterManager was initially founded under the name ISMA (International Ship Managers’ Association) in 1991, with the first steps in the creation of what is now known as InterManager beginning back in 1988 when five leading ship management companies – Barber International, Columbia Shipmanagement, Denholm Ship Management, Hanseatic Shipping Company, and Wescol International Marine – met to discuss the possibility of improving standards within the s

International Association of Dry Cargo Shipowners (INTERCARGO) represents the interests of quality dry cargo shipowners. INTERCARGO provides the forum where dry bulk shipowners, managers and operators are informed about, discuss and share concerns on key topics and regulatory challenges, especially in relation to safety, the environment and operational excellence.

International Association of Oil & Gas Producers (IOGP) are the global voice of their industry, pioneering excellence in safe, efficient, and sustainable energy supply - an enabling partner for a low carbon future. Their members, integrated energy companies, national oil companies, independent upstream operators, service companies, and industry associations operate around the globe, supplying over 40% of the world’s oil and gas demand.

International Chamber of Shipping (ICS) is the principal international trade association for the shipping industry, representing shipowners and operators in all sectors and trades. ICS membership comprises national shipowners'​ associations in Asia, Europe and the Americas whose member shipping companies operate over 80% of the world's merchant tonnage.

International Marine Supply Aps (IMS) was established in 1987 by Jens Boldreel which for many years had been a traditional general ship chandler. Martin Boldreel (son of Jens) joined the company in 1988 and the company began to concentrate on supplying ship spare parts primarily of Scandinavian origin.

International Seabed Authority (ISA) is an autonomous international organization established under the 1982 United Nations Convention on the Law of the Sea (UNCLOS) and the 1994 Agreement relating to the Implementation of Part XI of the United Nations Convention on the Law of the Sea (1994 Agreement).

The International Seafarers' Welfare and Assistance Network exists to improve the lives of seafarers and their families with services, resources, strategies and advocacy. ISWAN is a membership organisation with the International Chamber of Shipping, The International Transport Workers Federation and the International Christian Maritime Association as the core members.

Established in February 2019, iO3 PTE LTD. was established to adopt an innovative approach in the digital evolution for maritime customers today. They communicate and operate efficiently and safely in challenging maritime environments. Their digitalisation platform has been specifically designed to support enhanced integrated solutions, asset optimisation, and delivery of secured critical applications globally.

Irish Continental Group plc is the leading Irish-based maritime transport group. They carry passengers and cars, Roll on Roll off (RoRo) freight and Container Lift on Lift off (LoLo) freight, on routes between Ireland, Britain and Continental Europe. They also operate container terminals in the ports of Dublin and Belfast. The Group also carries out ship chartering activities.

Irish Ferries is an Irish ferry and transport company that operates passenger and freight services on routes between Ireland, Britain and Continental Europe, including Dublin Port–Holyhead; Rosslare Europort to Pembroke as well as Dublin Port-Cherbourg in France.

The Isalos.net initiative has as its main purpose the connection of the maritime community with the new generation while at the same time it is a knowledge platform for the developments and experiences from the maritime industry and maritime daily life.

Izumi Steel Works Ltd. was founded in 1961. The Company's line of business includes the manufacturing of steel castings including alloy, bushings, and rolling mill rolls.

James Fisher is a global provider of specialist services to the marine, oil & gas, and other high assurance industries worldwide. They offer innovative marine solutions and specialised engineering services, along with comprehensive products, services and support to the oil and gas, marine renewables, shipping and defence industries.

James Marine, Inc. was founded by C. Ronald James in 1986. The family-owned company began with twenty-five employees and has a proud history of extraordinary service and growth to the inland waterways. With over 1,300 employees in the JMI family of companies, they have 12 locations across Kentucky and Louisiana. They proudly promote a diverse workforce with an inclusive culture that encourages creativity and a positive team environment.

Japan CCS Co., Ltd (JCCS) was founded in May 2008 when a group of major companies with expertise in CCS-related fields, including electric power, petroleum, oil development, and plant engineering, joined forces to answer the Japanese government’s call for development of CCS technology as a countermeasure against global warming. JCCS is a unique company in the world to be founded and dedicated explicitly to developing integrated CCS technology.

Japan Engine Corporation is involved in the development, design, manufacturing, maintenance, repair, sale and licensing of engines and other components. From development to after-sales service, they are the only company in the world that has an integrated system of the UE engine, which is one of the world's three largest brands of low-speed marine engines.

jbj Techniques Limited offers a high level of in-house expertise plus a huge selection of products to meet a wide range of customer applications. From specification, through technical advice and manufacture to after-sales support, jbj Techniques provides a comprehensive and valued service to the mechanical power transmission and hydraulics industries. The company fields a UK-wide team of technical sales engineers to ensure business continuity.

JERA is the largest power generation company in Japan, producing about 30% of Japan's electricity.

JET-TECH (Jet-Tech Propulsion, LLC) is a volunteer network of local Information Technology (IT) professionals providing services to help people navigate the IT profession. They are experienced professionals who offer guidance to those considering entering the field, those with any amount of experience, and those looking to transition their careers.

Jumbo is a heavy lift shipping and offshore transportation & installation contractor. Jumbo has been developing pioneering solutions for ocean transportation for more than 50 years. Since 2003, building on their heavy lift capability, Jumbo rapidly established a sound track record in the offshore subsea installation market.

Kaiko Systems is an operational intelligence company that leverages manual operations to generate real-time insights for shipping companies to prevent incidents, increase operational efficiency, and reduce maintenance costs. With Kaiko Systems, crews are able to save 50% of the time on deck operations.

Founded in 1989, Kalgin Global Logistics has grown from a team of two with a small office on Sydney’s North Shore, to a passionate team of more than 40 professionals with offices in global locations, including Auckland, Brisbane, Melbourne, Sydney, Suva & Lautoka.

Kargosurge is a renowned logistics company with a strong focus on providing top-notch services to its clients. With years of experience in the industry, they have developed a deep understanding of the complexities involved in international shipping and logistics. Kargosurge offers a wide range of services that cater to the diverse needs of businesses across various industries.

Karstensen Kuldeteknikk AS are a global supplier of industrial freezing systems. Their extensive experience enables them to deliver different products to different industries. Fish processing, bakery, dairy and other are examples of this.

Together with about 100 group companies in Japan and overseas, Kawasaki Heavy Industries oversees the formation of a 'technology corporate group'.​ Their technological capabilities, polished over a history that exceeds a century, send diverse products forth into wide-ranging fields that go beyond land, sea, and air, extending from the ocean depths to space.

KBR, Inc. delivers science, technology and engineering solutions to governments and companies around the world. KBR employs approximately 29,000 people worldwide with customers in more than 80 countries and operations in 40 countries.

KJV A/S is one of the country's renowned suppliers of products within machining, transmission, automation, tools, technical articles and machine tools. Their focus is on improving their customers' competitiveness and bottom line through forward-thinking advice, innovative products, timely delivery and competitive prices.

Kongsberg Maritime is a world leader in marine technology. With an extensive portfolio of innovative and integrated products and solutions, Kongsberg Maritime delivers efficiency, reliability, flexibility, and environmental sustainability to enhance the business of its customers.

KPI OceanConnect is one of the world’s largest and most experienced independent marine fuels service and solutions providers, established by the merger of KPI Bridge Oil and OceanConnect Marine. Their dedicated global team of 170 experienced professionals has delivered trusted expert advice and services to the international shipping community since 1971.

With headquarters in Austria, KRAL GmbH was founded in 1950 and has been an independent family enterprise ever since. KRAL develops and produces screw pumps and flow measurement technology. In addition, they offer customer-specific solutions for systems, from the initial engineering process through to commissioning.