Which vessel category cannot show a draft restriction?

Answer: C — sailing vessel under sail

A sailing vessel under sail cannot show a draft restriction because it is typically not limited by its draft as a constraint for navigation. Instead, such vessels are usually governed by their means of propulsion and are thus able to maneuver more flexibly in various water depths. In contrast, the other vessel categories mentioned do have specific characteristics that could impose draft restrictions. For example, a vessel constrained by her draft operates in shallow waters where a deep draft could hinder navigation or risk grounding. Similarly, a tug and tow combination must consider the draft of both the tug and the tow when navigating, as their combined draft can affect their ability to safely traverse certain waters. A fishing vessel may also have draft considerations due to its operational needs and the water depths required for efficient fishing activities. Therefore, the distinction lies in the operational nature of a sailing vessel, as it is less likely to experience limitations rooted in draft compared to the other types listed.