A marine diesel engine is a type of internal combustion engine specifically designed for use in ships and boats. It operates by burning diesel fuel to produce power, which is then used to drive the vessel's propeller or generate electricity. These engines are known for their efficiency, durability, and ability to operate in harsh marine environments. Marine diesel engines come in various sizes and configurations, ranging from small engines for recreational boats to large engines for cargo ships. They are typically more fuel-efficient than gasoline engines and produce less carbon monoxide, making them a popular choice for marine applications.