COLREGs and their application in collision avoidance algorithms: A critical analysis

• Published in: Ocean engineering 2022-10, Vol.261, p.112029, Article 112029
• Main Authors: García Maza, Jesús A., Argüelles, Reyes Poo
• Format: Article
• Language: English
• ISSN: 0029-8018; 1873-5258
• DOI: 10.1016/j.oceaneng.2022.112029

Ship collisions are some of the biggest risks in shipping, and Decision Support System/Collision Avoidance-Alert Systems (DSS/CAS) are being developed to prevent and avoid them. They must become an essential equipment for any vessel, especially for Maritime Autonomous Surface Ships (MASS). Assuming the Convention on the International Regulations for Preventing Collisions at Sea, 1972 (COLREG 72) as the basis for every DSS/CAS, there is growing concern in the maritime field about the lack of consistency of published studies, in particular those on the design of algorithms for the control of ship collision avoidance manoeuvres, with the requirements of the current COLREG. The methods applied for the assessment of scenarios and situations will be analyzed, since only a correct appraisal of the circumstances will bring about the adequate response for such critical situations. COLREG is conceived to always have the Officers Of the Navigational Watch (OONW) (more specific than the overly generic expression Officer On Watch -OOW), at the center of every decision. Therefore, in the design of a DSS/CAS, interpretations that approach collision situations from a different perspective than that of an OONW should be avoided. Safe communication with other vessels would reinforce and improve the information available to the OONW. This paper aims to offer an insight into ship collisions avoidance according to COLREG 72 that may prove useful to the OONWs either on board or remotely, or even to autonomous systems. It is illustrated by examples taken from some works which, despite their great influence in the current literature, do not have a correct standpoint. •Identification of basic criteria to consider when making decisions in vessel encounters in accordance with COLREG.•Identification of COLREGs' weaknesses/ambiguities, to unify patterns for the development of collision avoidance algorithms.•Identification of possible problems of interpretation and some common mistakes found in recent or remarkable literature.