What does "engaged in fishing" mean for a vessel?

The phrase "engaged in fishing" refers specifically to vessels that are actively involved in catching fish or other marine life for commercial or recreational purposes. This typically means the vessel is using multiple fishing lines, nets, or other gear designed to capture fish. Option B accurately reflects this definition because it encompasses vessels utilizing more than one line or net, indicating an active fishing operation.

Other options do not align with the meaning of "engaged in fishing." For example, a vessel limited to one fishing line would not sufficiently capture the broader scope of activities involved in commercial or active fishing. Similarly, a vessel that is transporting passengers is engaged in a different activity altogether, likely falling under passenger transport regulations rather than fishing regulations. Lastly, maneuvering at high speed is irrelevant to the fishing activity, as it pertains to the vessel's operation rather than its purpose of being involved in fishing. Therefore, option B is the best representation of what it means for a vessel to be "engaged in fishing."