Effects of Hull Form and Propulsion Power Characteristics on the Maneuvering Performance of Large Fishing Vessels

The maneuverability standards established by the International Maritime Organization (IMO) primarily address merchant ships, while large fishing vessels generally fall outside their scope. This study investigated the relationships between selected design characteristics and maneuvering performance using full-scale trial data from four large fishing vessels. Their principal design characteristics and maneuvering indices were compared with the distributions of a 226-ship merchant-ship database and with four reference merchant ships for which complete design and trial data were available. The fishing-vessel cases were positioned toward the lower ranges of the available merchant-ship distributions for L/B and Cb/(L/B), whereas their B/d values substantially overlapped the principal merchant-ship range. Their P/Δ values were higher than those of the four reference merchant ships. Within the four fishing-vessel cases, B/d and P/Δ showed the most apparent tendencies with the Turning indices, L/B and Cb with the Zig-zag Overshoot angles, and Cb and P/Δ with Track reach/L. These observations indicate that the design variables associated with the most apparent tendencies differed among turning, course-checking, and stopping responses. Although the limited dataset does not permit statistical generalization or the establishment of causal relationships, the results suggest that the maneuvering characteristics of large fishing vessels are better characterized by considering combined hull-form and propulsion characteristics together with the balance among multiple maneuvering responses, rather than by interpreting individual design variables in isolation. These full-scale observations provide a basis for further systematic investigation and maneuverability assessment of large fishing vessels.