Question 1

The Correct Answer is B **Explanation for Option B ("Vessel constrained by her draft"):** The term "vessel constrained by her draft" is explicitly defined in Rule 3(k) of the **International** Navigation Rules (COLREGs), which apply on waters outside the demarcation lines (international waters). This term is **not** defined or used in the official text of the **Inland** Navigation Rules, which apply on the navigable waters shoreward of the demarcation lines. The Inland Rules recognize "vessel restricted in her ability to maneuver" but omit the category of "vessel constrained by her draft." **Explanation for Incorrect Options:** * **A) Seaplane:** This term **is** defined in the Inland Navigation Rules, specifically in Rule 3 ("General Definitions") as a term used in the Rules for "aircraft on the water." * **C) Restricted visibility:** This term **is** defined in the Inland Navigation Rules, specifically in Rule 3 ("General Definitions") as "any condition in which visibility is restricted by fog, mist, falling snow, heavy rainstorms, sandstorms or any other similar causes." * **D) Underway:** This term **is** defined in the Inland Navigation Rules, specifically in Rule 3 ("General Definitions") as meaning that "a vessel is not at anchor, made fast to the shore, or aground."