Analisis Seakeeping Kapal Fiberglass 1 GT Akibat Penambahan Panjang (Studi Kasus Kapal Custom Rod)

Fiberglass vessels are an important means in Indonesian fisheries, thus studies on seakeeping and resistance are required to ensure safety and operational efficiency. This research aims to analyze the effect of extending the Custom Rod vessel from 5.83 m to 7.32 m through modeling using Maxsurf Motion and Maxsurf Resistance. The modification was carried out with the expectation of improving the vessel’s motion characteristics. The results showed that heave acceleration significantly decreased from 1.143 g to 0.108 g, thereby meeting the comfort criteria according to Tello et al. Roll motion remained stable below the 6.0° threshold,while pitch still did not meet the criteria at angles of 135° and 180°. In terms of resistance, the vessel before modification was able to reach 23 knots with a power requirement of 41.649 hp, whereas after modification it only achieved 19 knots with a power requirement of 41.629 hp. Therefore, to reach 25 knots, a larger engine power of approximately 78 hp is required. In conclusion, the length
extension of the vessel proved effective in improving heave and roll characteristics, but it had a negative impact on pitch and reduced speed performance due to the increase in power demand.