Which term describes a vessel constrained by draught?

The term "vessel constrained by draught" refers to a situation where a ship's ability to navigate is limited due to its depth below the waterline. This typically occurs in shallow waters where the vessel cannot easily change course or speed without risking grounding. A vessel constrained by draught is therefore considered "restricted in her ability to maneuver."

In contrast, the other options refer to distinct categories of vessels or operational modes, none of which specifically capture the limitations imposed by a vessel's draught. For example, a vessel operating under sail only refers to sailboats and does not imply any constraints related to draught. Similarly, a vessel propelled by machinery highlights the method of propulsion rather than its maneuverability issues. Lastly, a vessel engaged in fishing activities is specific to its function and does not inherently indicate limitations due to draught. Thus, the correct designation of a vessel constrained by draught is indeed that it is restricted in its ability to maneuver.