Established as a non-governmental organization (NGO) in Canada in 2004, the International Dialogue on Underwater Munitions (IDUM) underwent a transformative shift in 2014, evolving into a Dutch Foundation headquartered in The Hague, The Netherlands. Serving as a voluntary collaborative platform, IDUM actively engages in a spectrum of areas related to sea-dumped munitions, encompassing policy, science, technology, and response strategies.The organization's inception can be attributed to Terrance P. Long, a retired Canadian Military Engineer with an extensive background spanning over three decades in Explosive Ordnance Disposal and demining worldwide. Fuelled by his profound expertise and unwavering commitment to marine ecosystems, IDUM was founded under his visionary leadership.Terrance P. Long's involvement extends beyond IDUM, encompassing roles such as Chair of the International Science & Technology Advisory Board (ISTAB) in The Netherlands, participation as Heads of Delegation/Observer in the Helsinki Commission (HELCOM) for the Protection of the Baltic Sea and the OSPAR Commission for the Protection of North-East Atlantic Oceans, and observer status at the International Seabed Authority (ISA) in Kingston, Jamaica. Accredited to High-Level United Nations Oceans Conferences and Sustainable Development Goals (SDGs) 13 (Climate Action) & SDG 14 (Life below water), he also founded and hosted seven International Dialogues on Underwater Munitions.Terrance P. Long's noteworthy achievements include nominations for the Prince's Trust Canada Veteran Entrepreneur Award in 2023, recognition by the Royal Canadian Mint with the "Protecting the Ocean Rare Coin" for tireless ocean conservation efforts, and The Hague OPCW Award to CWC-IDUM for the Elimination of Chemical Weapons.