Final answer:
A "power-driven vessel" is any vessel with propelling machinery on board, irrespective of whether the machinery is currently in use or not. Option D is correct.
Step-by-step explanation:
The designation "power-driven vessel" encompasses any watercraft that is equipped with on-board propelling machinery, irrespective of whether the machinery is actively engaged or not. This definition broadly includes various types of vessels utilizing diverse power sources for propulsion, such as those employing steam power, internal combustion engines, and even nuclear power. The key criterion for falling within this category is the presence of machinery capable of propelling the vessel.
Examples of power-driven vessels range from traditional ships utilizing steam engines or internal combustion engines to more modern vessels powered by nuclear propulsion systems. These vessels feature turbines intricately connected to a propeller mechanism. In operation, the rotating shaft of the turbine imparts motion to the propeller, propelling the vessel through water. Notably, the classification as a power-driven vessel underscores the vessel's ability to navigate independently of external forces like currents, owing to the self-contained power source.
In essence, the term "power-driven vessel" is an inclusive categorization that spans a spectrum of watercraft employing various propulsion technologies. It highlights the significance of on-board machinery capable of generating propulsive force, contributing to the vessel's self-sufficiency and ability to traverse water under its own power.