What vessels require a licensed driver?

A licensed driver is required for all vessels with motors greater than 6 horsepower because these vessels can pose a greater risk due to their speed and operational complexity. The requirement for a license ensures that the operator has received proper training and understands safety regulations, navigational rules, and emergency procedures. This is particularly important for larger or more powerful vessels, which can cause serious accidents if operated irresponsibly.

While personal watercraft (PWC) need a licensed operator in Queensland, the law specifically emphasizes the motor size when determining the need for a license. Vessels under 10 meters in length do not necessarily require a license unless they also exceed the specified horsepower threshold. Moreover, commercial vessels have their own licensing requirements due to their operating nature, which often necessitates additional qualifications beyond what is required for recreational vessels. Thus, the requirement for a license primarily hinges on the motor's power output, as stated in the correct option.