All 21 cards in this deck
The complete deck. Click any question to see the answer — useful for browsing,
searching the page, or printing. The other decks are linked above; together they cover
all 721 cards.
Inland vs. International
33 CFR 83 · 21 cards
Where do the Inland Rules apply?
Shoreward of the COLREGS Demarcation Lines — on U.S. inland waters, the Great Lakes, and the Western Rivers. Seaward of those lines the International Rules apply. The lines are charted, and they are the only thing that decides which regime you are under.
Rule 1 — Application
What are the "Western Rivers" under the Inland Rules?
The Mississippi River and its tributaries, South Pass and Southwest Pass to the demarcation lines, the Port Allen–Morgan City Alternate Route, and the Atchafalaya River above its junction with that route, including the Old River and the Red River. Several Inland rules apply only there (and on the Great Lakes).
Rule 3 — General Definitions
Great Lakes or Western Rivers: who has right of way, upbound or downbound?
The downbound vessel — the one running with a following current — has the right of way. She proposes the manner and place of passage and initiates the maneuvering signals. The upbound vessel holds as necessary to permit safe passing. This overrides both the keep-right rule and Rule 14.
Rule 9 — Narrow Channels
Inland Rule 15(b): crossing a river on the Great Lakes or Western Rivers.
A power-driven vessel crossing a river shall keep out of the way of a power-driven vessel ascending or descending the river — regardless of which side she is on. The ordinary crossing rule does not decide it.
Rule 15 — Crossing Situation
Which Rule 18 category does NOT exist in the Inland Rules?
Vessel constrained by her draft. Inland Rule 18(d) is simply [Reserved], and Inland Rule 28 (her lights) is Reserved too. The category, its definition, and its three all-round red lights are International only.
Rule 18 — Responsibilities Between Vessels
Inland sound-signal equipment thresholds.
12 m or more: whistle. 20 m or more: bell as well. 100 m or more: gong in addition. The bell threshold is the trap — International requires it from 12 m, Inland from 20 m.
Rule 33 — Equipment for Sound Signals
What do one and two short blasts mean under the INLAND Rules?
One short: "I intend to leave you on my port side." Two short: "I intend to leave you on my starboard side." Three short: "I am operating astern propulsion." These state an intention — International states an action already being taken.
Rule 34 — Maneuvering and Warning Signals
When do the Inland maneuvering signals apply?
When power-driven vessels are in sight of one another and meeting or crossing within half a mile of each other. The International rule has no distance limit and no agreement requirement.
Rule 34 — Maneuvering and Warning Signals
Under Inland Rules, what does the other vessel do when it hears your one-blast signal?
If she agrees, she sounds the same signal back and takes the steps needed for safe passing. If she doubts the safety of the proposal she sounds the danger signal (five or more short rapid blasts), and both vessels take precautionary action until a safe passing agreement is made.
Rule 34 — Maneuvering and Warning Signals
The Inland overtaking signals.
One short = "I intend to overtake you on your starboard side." Two short = "on your port side." The vessel being overtaken sounds a similar signal if she agrees, or the danger signal if in doubt. Not the International two-prolonged-plus-short signals.
Rule 34 — Maneuvering and Warning Signals
Inland only: what signal does a vessel sound when leaving a dock or berth?
One prolonged blast. There is no such requirement in the International Rules.
Rule 34 — Maneuvering and Warning Signals
Inland only: can a radiotelephone agreement replace the whistle signals?
Yes. A vessel that reaches agreement in a head-on, crossing, or overtaking situation — for example by VHF under the Vessel Bridge-to-Bridge Radiotelephone Act — is not obliged to sound the whistle signals, though she may. If agreement is not reached, whistle signals shall be exchanged in a timely manner and shall prevail.
Rule 34 — Maneuvering and Warning Signals
Inland light signals supplementing the whistle — what color and range?
An all-round white or yellow light, visible at least 2 miles, synchronized with the whistle, each flash about 1 second. International specifies an all-round white light visible at least 5 miles.
Rule 34 — Maneuvering and Warning Signals
What is a "special flashing light," and which regime has it?
Inland only. A yellow light flashing at 50 to 70 flashes per minute, placed as far forward as practicable on the centerline of the tow, showing over an arc of not less than 180° nor more than 225° — from right ahead to no more than 22.5° abaft the beam on either side.
Rule 21 — Definitions
Which vessels carry the special flashing light?
A vessel being pushed ahead (not part of a composite unit) shows sidelights and a special flashing light at the forward end. A vessel towed alongside shows a sternlight and, at the forward end, sidelights and a special flashing light.
Rule 24 — Towing and Pushing
Inland only: the special anchorage area exemption for anchor lights.
A vessel of less than 20 m at anchor in a special anchorage area designated by the Coast Guard need not exhibit anchor lights or shapes. (The general Rule 30 exemption, in both regimes, is for vessels under 7 m away from a channel, fairway, anchorage, or where vessels normally navigate.)
Rule 30 — Anchored Vessels and Vessels Aground
Inland only: which moored barges must be lit, and with what?
Barges projecting into a buoyed or restricted channel; barges moored so as to reduce the navigable width to under 80 m; barges moored in groups more than two wide or over 25 m wide; and any barge not moored parallel to the bank or dock. Each shows two all-round white lights visible at least 1 nautical mile.
Rule 30 — Anchored Vessels and Vessels Aground
Inland only: who is excused from the anchored-vessel fog bell in a special anchorage?
A vessel of less than 20 m, and a barge, canal boat, scow, or other nondescript craft, when anchored in a Coast Guard–designated special anchorage area.
Rule 35 — Sound Signals in Restricted Visibility
A 15 m vessel at anchor in fog under the Inland Rules — what must she sound?
She is not obliged to give the bell signal (that duty starts at 20 m), but if she does not, she must make some other efficient sound signal at intervals of not more than 2 minutes. The same applies to vessels under 12 m.
Rule 35 — Sound Signals in Restricted Visibility
How does Inland Rule 36 differ from International Rule 36?
Both allow signals that cannot be mistaken for an authorized signal, and both allow directing a searchlight toward the danger without embarrassing any vessel. The International rule adds two sentences the Inland rule does not have: the light must not be mistakable for an aid to navigation, and strobes shall be avoided.
Rule 36 — Signals to Attract Attention
Air-cushion vessel in non-displacement mode — what light, and in which regime?
An all-round flashing yellow light, in both regimes. Inland adds "where it can best be seen." A WIG craft taking off, landing, or in flight near the surface shows a high-intensity all-round flashing red light in both.
Rule 23 — Power-driven Vessels Underway
Study aid only — it certifies nothing. Content is checked against the U.S. Coast Guard
Navigation Rules and Regulations Handbook (corrected 12 August 2024), covering the
72 COLREGS as amended through IMO Resolution A.1085(28) and the Inland Rules at 33 CFR Part 83.
The governing text is the handbook, not this page.
Read it at the USCG Navigation Center.
