The cost of cyber attacks worldwide is startling, with global costs from cyber crime predicted to exceed USD 10 trillion by 2025. Although shipping remains a small part of this total, cyber attacks in the maritime industry are becoming increasingly costly. Recent data shows that a cyber attack now costs the targeted organisation an average of USD 550,000. This is not a new threat, the International Maritime Organization (IMO) recognised this and in January 2021 mandated the integration of cyber risk management into a company’s Safety Management System (SMS). This need for cyber risk management was further clarified by ‘Guidelines on Maritime Cyber Risk Management’, with the latest version published by the IMO in June 2022. Technological advances are progressing rapidly. Achieving the potential gains in efficiency, operations, and safety requires a high degree of connectivity between ships and external services. The challenge lies in protecting ships, without restricting the benefits a connected ship brings. INFORMATION TECHNOLOGY AND OPERATIONAL TECHNOLOGY The use of computerised systems on board a ship can effectively be split into two separate functions, Information Technology (IT) and Operational Technology (OT). IT can be considered the typical office functions that take place on board ships; this may include the email communication and data reporting/sharing that companies use. As this technology has a longer history and experience of being connected to external sources and transmitting data, cyber security safeguards are better understood, and personnel are more alert to the associated hazards. OT, on the other hand, is what controls many of the ships systems, such as the main engine control, or dynamic positioning. This equipment was traditionally considered safer due to the lack of external connectivity; however, this is rapidly changing and can provide an entry point for malicious activity. As the threat has become clearer and the potential for safety, environmental, and economic damage better understood, the demand for clear defensive actions have grown. As the cyber threat frequently innovates and adapts, there are no prescriptive procedures that will provide sufficient security. Therefore, it is necessary for those involved in shipping to develop cyber resilience. INTERNATIONAL ASSOCIATION OF CLASSIFICATION SOCIETIES UNIFIED REQUIREMENTS (IACS) The IACS has produced two Unified Requirements (UR) that will be implemented on all ships contracted for construction on or after 1 July 2024. While mandatory for new ships, the content of these UR’s provides useful information and guidance for protecting ships currently in service. UR E26 Rev1 provides requirements for a ship to be considered cyber resilient. Along with more information, it details the functional aspects that must be addressed for adequate cyber security. The five functional elements, and some considerations include: IDENTIFY This involves identifying the vulnerabilities in the ship’s systems. It means having detailed inventories of all computer equipment, operating systems, software, etc. Clear plans should show the location of all equipment, including any interconnections between systems. A robust management of change procedure should be established to keep systems up to date, whilst preventing any disruption. PROTECT Establish fixed boundaries between critical networks to allow zero or minimal permitted traffic between these individual ‘zones’. Access to networks