ABSTRACT
An important concept when addressing ship collision problems is the concept of ship domain. Fujii & Tanaka (1971) developed models to determine the traffic capacity of a route or waterway which used the concept of ship domain, as an area around the vessel which the navigator would like to keep free of other vessels, for safety reasons. Goodwin (1975) also used this concept in collision assessment models. Several shapes have been proposed for ship domains, such as circular, elliptical or polygonal. Fuzzy ship domains, such as proposed by Pietrzykowski et al. (2008) have introduced a higher level of sophistication to the concept, by creating different levels of safety within the domain, rather than using a binary classification (safe or unsafe) for a given situation. Ship domain models depend on the definition of the size of the domain, which may present significant variations (Wang et al. 2009).
