Question 16 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is B **Explanation for Option B (The Mississippi River System) being Correct:** The Inland Navigation Rules (33 CFR Subchapter E, specifically Rule 3, Definitions) apply to "inland waters." The boundary lines defining these inland waters are explicitly detailed in 33 CFR Part 89 (Inland Navigational Rules Act of 1980 Boundary Lines). These boundary lines generally delineate waters shoreward of specific geographic lines from the high seas/international waters. The Mississippi River System, including all its navigable tributaries, locks, and dams, lies entirely within these designated boundary lines and is therefore considered part of the "Inland Waters" for the purpose of the Inland Navigation Rules. **Explanation of Why Other Options Are Incorrect:** * **A) The Great Lakes in their entirety:** This is incorrect because the Great Lakes are subject to a specific boundary determination. While the waters shoreward of the Demarcation Lines (e.g., at the entrances to harbors and rivers leading into the lakes) are inland waters, the main body of the Great Lakes themselves (except for waters designated as "Western Rivers") are generally considered Great Lakes waters, and the rules apply differently (sometimes using the International Rules structure depending on the specific location on the lakes, but always defined by the Inland Rules jurisdiction up to the international boundary line). Crucially, the entirety of the Great Lakes is not simply defined as "Inland Waters" in the same way as a closed river system like the Mississippi. * **C) U.S. waters out to three miles offshore:** This is incorrect. The boundary between Inland Waters and International Waters is *not* a uniform three-mile line. Instead, the boundary is defined by specific, established demarcation lines (as detailed in 33 CFR Part 89) that often cross bays, estuaries, and harbor mouths much closer to shore than three miles. Waters seaward of these specific demarcation lines are subject to the International Regulations for Preventing Collisions at Sea (COLREGS). * **D) The St. Lawrence River to Anticosti Island:** This is incorrect. The boundary between Inland Waters and International Waters on the St. Lawrence River is specifically designated at a line drawn across the river near **Cape Sorel** (near Quebec City), far upstream from Anticosti Island. Seaward of this designated demarcation line, vessels must comply with the International Regulations for Preventing Collisions at Sea (COLREGS).