Yacht maintenance is a process performed to keep all devices on a yacht working efficiently and for keeping the smoothness of underwater parts of a yacht. Underwater parts of a yacht are prone to marine growth. Marine growth increases the friction of the underwater surface, which in turn creates resistance to movement of a yacht through water. Overcoming of this resistance increases the fuel expenditure of yacht engines. A yacht with less resistance of underwater parts will use less fuel traveling the same distance as a yacht with more resistance. Term yacht in this thesis is defined as in Croatian maritime law. The goal of this thesis is to evaluate the level of modernization and efficiency of underwater maintenance process for yachts performed in Splitsko-dalmatinska region. Evaluation is based on the investigation of every part of a process. Every part of a process is elaborated in a special chapter: lifting of the yacht from the sea (with or without the use of travel lifts), cleaning, grinding, repairing and coating. If this process is done regularly and well it will drastically contribute to the overall performance of a yacht. Primarily it affects the speed and fuel expenditure. In conclusion, this process in Splitsko-dalmatinska region is efficient and modernized.