Marine debris poses significant challenges to the operational efficiency of the Magogoni Ferry in Dar es Salaam, Tanzania. This study investigates the sources of marine debris in the ferry's operational environment and evaluates their effects on operational efficiency. Field surveys, interviews, observations, and document reviews were conducted to identify debris sources and quantify their impacts on ferry operations. Findings indicate diverse debris origins, including urban waste, coastal littering, and shipping activities, contributing to operational disruptions through increased maintenance needs and service delays. The study underscores the importance of debris management strategies for sustaining ferry operations. It was found that a large quantity of marine debris reaching the Magogoni Ferry was brought by rivers during the rainy seasons, namely River Tegeta, River Mzinga, and River Msimbazi. Marine debris which impairs ferry operations at Magogoni Ferry includes fishing lines, fishing nets, wood, ropes, textiles, and plastic bags. The effects were seal damage, pump jet blockage, impeller entanglement, mechanical obstruction of the pump jet, and engine stoppage. These breakdowns cause navigational hazards, environmental pollution due to oil leakages, and increased costs of maintenance. It was found that between 2019 and 2023, the cost of maintenance due to breakdowns, whose sources were established to be marine debris, amounted to an average of Tsh120 million per year. to ensure the ferry channel is safe for navigation it was recommended to make it free from debris through implementing educational campaigns to raise awareness, regular cleaning, prohibiting fishing by angling near the ferry area, and the use of technology both to block the entrance of land-based waste to the sea and to improve ferry systems by making them able to withstand debris challenges, for example, the introduction of cutting blades to cut nets, ropes, and fishing lines, protecting the propulsion components.