  Over the past few years, we have seen several cyber incidents being reported,
where some of the primary causes were the lack of proper security controls
onboard the ship and crew awareness on cybersecurity. In response to the
growing cyber threat landscape in the maritime sector, we have developed a set
of guidelines for maritime cyber risk management, focusing on four major
shipboard Operational Technology (OT) systems that are crucial for the
day-to-day operation of ships. These four OT systems are: Communication
Systems, Propulsion, Machinery and Power Control Systems, Navigation Systems
and Cargo Management Systems. The guidelines identify the cyber risks in each
of the OT systems and recommend the necessary actions that can be taken to
manage risks in each shipboard OT system. In this paper, we introduce the new
guidelines, which include cyber risks, mitigation measures, cyber risk
assessment, and a checklist to help shipowners and maritime authorities assess
and enhance cyber hygiene of their vessels. Our guidelines have been
disseminated by the Maritime and Port Authority of Singapore (MPA) to owners
and operators of the Singapore Registry of Ships for their reference and use.
