Which of the following best describes hovercraft according to the vessel definition?

Hovercraft are classified as non-displacement craft because they operate by creating a cushion of air underneath their hull, allowing them to move over water and land without displacing the water like traditional boats do. This unique principle of operation distinguishes them from traditional vessels that rely on buoyancy and displacement to float.

In contrast to the other options, which either limit the characteristics or applications of hovercraft incorrectly, the categorization as non-displacement craft accurately reflects their design and operational capabilities. Hovercraft can navigate both shallow and deep waters, and while they can be used recreationally, they also have significant commercial and emergency applications. Moreover, the requirement for a crew is dependent on the specific use and regulations governing individual crafts, rather than a blanket requirement applicable to all hovercraft.