Observation and assessment of crossing situations between pleasure craft and a small passenger ferry

Abstract

A study of navigational situations involving a small passenger ferry ‘Ole III’ was conducted based on participatory observations in the Husøysund strait in Tønsberg municipality, Norway. The aims were to document the extent to which crossing situations are solved according to navigational rules and practice, and to investigate the number of incidents which could pose a risk for Ole III and its passengers. Because of the high density of private pleasure craft, we expected a rather large number of non-compliance with navigational rules. Observations supported this assumption, and based on the total of 3152 crossings with Ole III where other vessels where present, a total of 279 (8.9%) incidents were considered to involve non-compliance with navigational rules and practice. A total of 165 incidents were caused by the other vessels failing to give way even though it had Ole III on its starboard side. This indicates that, at least in Norway, we may routinely expect pleasure craft to deviate from navigational rules for crossing situations. A number of incidents could partly be explained by a mismatch in understandings of which vessel had the right-of-way. Also, incident risk was higher when Ole III used active control strategies to handle crossing situations (e.g. keeping course and speed) as compared with passive control strategies. A taxonomy of situations based upon intentions is presented together with suggestions for control strategies for small passenger vessels that operate in waters with many pleasure craft.