Smooth and efficient cargo operations are crucial in tanker shipping, and one of the main factors that determine them is the effectiveness of tank cleaning, the process of removing the residues of the previous cargo before a new cargo is loaded. On tankers carrying palm oil products, such as crude palm oil (CPO) and crude palm kernel oil (CPKO), cargoes change frequently, and inadequate cleaning can contaminate the new cargo, lead to claims by charterers, and delay loading. This study analyses the implementation of tank cleaning on the MT Bahari Maju II, identifies the factors that hindered it, and proposes measures to make it more effective and efficient. A qualitative descriptive design was used, with data collected through observation of tank cleaning operations, interviews with the Chief Officer, the Second Officer, and three able seamen, and documentation during the authors’ sea practice. The results show that tank cleaning was hindered by two main factors. First, the deck crew lacked the knowledge and experience needed for tank cleaning; three of the helmsmen were new to tankers, some crew members could not correctly explain the protective equipment or the authority responsible for the operation, and residues of water, sand, and rust were found in the suction wells. Second, the time available was limited: the passage from the port of discharge to the port of loading took about 2 days and 12 hours, during which four tanks had to be prepared for CPKO at an estimated four hours of washing per tank, in addition to ventilation, drying, inspection, and the crew’s watchkeeping and rest periods. Closer supervision by the Chief Officer, including inspection of the tanks and suction wells, a written tank cleaning plan, familiarisation training for crew new to tankers, stricter selection of competent deck crew, and compliance with MARPOL Annex II and the cargo interests’ requirements for previous cargoes are recommended.