In fish farms, a major issue is the net cage wear, resulting in fish escapes and negative impact on fish quality, due to holes and biofouling of the nets. To minimize fish losses, fisheries utilize divers to inspect net cages on a weekly basis. Aquaculture companies are looking for ways to maximize profit, and reducing maintenance costs is one of them. Kefalonia Fisheries spend 250,000 euros yearly on diver expenses for net cages maintenance. This work is about the design, fabrication, and control of an inexpensive autonomous underwater vehicle (AUV) intended for inspection in net cages at Kefalonia Fisheries S.A. in Greece. Its main body is 3D printed, and its eight-thruster configuration grants it six degrees-of-freedom. The main objective of the vehicle is to limit maintenance costs by increasing inspection frequency. The design, fabrication, electronic components, and software architecture of the AUV are presented. In addition, the forces affecting kalypso, mobility realization, navigation, and modeling are quoted along with a flow simulation and the experimental results. The proposed design is adaptable and durable while remaining cost-effective, and it can be used for both manual and automatic operations.