Ships have an important role in fishing operations, because ships are an aspect that determines success in the fishing proses. In order for a gillnet vessel to operate properly, it must have a large length, moderate width, and small draft height because these three values are the main values for ship dimensions. In designing fishing vessels, there are several stages, namely calculating the main dimensions, making lines plan, and calculate the resistance experienced by the ship. This study aims to determine the main dimensions of fishing vessels from gross tonnage in the Karangsong area, as well as to draw a line plan for the main sizes of fishing vessels and determine the resistance of vessels at their service speed. This research was conducted in the Karangsong Indramayu area from March to June 2023. The results of the research on the main sizes of fishing vessels with gillnets are L= 18,1 m, B= 4,6 m, D= 1,8 m, service speed boats designed to range from 0 to 12 knots using the holtrop method, the drag at a speed of 6 knots is 2,5 kN, at a speed of 9 knots is a 16,1 kN, and at a speed of 12 knots it is 49,3 kN.

Welding is an important thing in shipbuilding. There are several types of joints and types of materials with different material thicknesses, on of which is Flux Cored Arc Welding (FCAW). FCAW is a welding process that has a high level of productivity so that it is suitable for fabrication activities. Double-sided welding is often performed on joints. This causes time inefficiencies and costs quite a lot. Therefore, the solution so that welding is only done on one side, by using a backing ceramic. The Backing Ceramic is used to hold the welding penetration better and get better welding result. The purpose of this study was to determine the result of the strength of Backing Ceramic Weld on FCAW welding of A36 carbon steel material so that it can get perfect results, not defective and can be accepted according to the desired criteria.

Vibration due to misalignment of the propeller shaft is detected using the VA-12 Vibration Analyzer sensor which is equipped with a Piezoelectric Accelerometer PV-571. Vibration measurements are carried out in alignment and misalignment conditions. The VA-12 Vibration Analyzer detection tool displays the results of the Vibration signal. Must be protected against the vibrations generated. Vibration signal analysis is done by looking at or observing the signal amplitude and signal frequency with two conditions of alignment and misalignment. The VA-12 Vibration Analyzer is used to analyze vibration signals and then convert them to Fast Fourier Transform (FFT) and Wavelet Transform (WT). In this analysis, a comparison of vibrations is carried out during alignment and misalignment conditions.

Shipyards are often difficult to find information quickly and efficiently on every component of the workplace. A good information system is actually needed for the work process in the shipyard because the project head's planning for the distribution of the project workload being carried out will result in a smooth production process, which will affect the completion time of the work to be carried out. Each of these stages is the final result stage where at this stage the author will draw conclusions to answer the formulation of the packing report based on writing which is prone to loss and damage. The development of an android-based ship repair information system that can be used to quickly and accurately report data required by the central supervisor allows for full monitoring of the new ship building process, which is standard practice in many shipyards that have a research methodology to solve the problem.