Rule 9 — Narrow Channels

TL;DR — In a narrow channel or fairway, keep to the starboard side as near as is safe and practicable; on the Great Lakes, Western Rivers, and Secretary-designated waters, a downbound vessel with a following current has the right-of-way over an upbound vessel and initiates the passing signals. 33 CFR §83.09

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What the Rule Says

Starboard-side requirement

Every vessel proceeding along the course of a narrow channel or fairway shall keep as near to the outer limit of the channel or fairway which lies on her starboard side as is safe and practicable. 33 CFR §83.09 This is the foundational obligation of Rule 9 and applies to all vessels — power-driven, sailing, fishing, or otherwise — when transiting a narrow channel.

Inland-only: downbound right-of-way on Great Lakes, Western Rivers, and Secretary-designated waters

Notwithstanding the general starboard-side rule and the head-on rule of Rule 14, a power-driven vessel operating in narrow channels or fairways on the Great Lakes, the Western Rivers, or waters specified by the Secretary, and proceeding downbound with a following current, shall:

1. Have the right-of-way over an upbound vessel; 2. Propose the manner and place of passage; and 3. Initiate the maneuvering signals prescribed by Rule 34(a)(i).

The vessel proceeding upbound against the current shall hold as necessary to permit safe passing. 33 CFR §83.09

This provision is unique to the Inland Rules and has no direct counterpart in the International Regulations. The definitions of Western Rivers and Great Lakes are found in Rule 3. 33 CFR §83.03

Vessels that must not impede

Rule 9 places explicit "shall not impede" obligations on three categories of vessels:

• A vessel of less than 20 meters in length or a sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway. 33 CFR §83.09
• A vessel engaged in fishing shall not impede the passage of any other vessel navigating within a narrow channel or fairway. 33 CFR §83.09

Note carefully: "shall not impede" is a distinct obligation from "keep out of the way." A vessel that must not impede must take early action to avoid even creating a close-quarters situation; it does not simply yield at the last moment.

Crossing a narrow channel

A vessel must not cross a narrow channel or fairway if such crossing impedes the passage of a vessel which can safely navigate only within that channel or fairway. If the vessel that can only navigate within the channel is in doubt as to the intention of the crossing vessel, it must use the doubt/danger signal prescribed by Rule 34(d). 33 CFR §83.09

Overtaking in a narrow channel

When a power-driven vessel intends to overtake another power-driven vessel in a narrow channel or fairway, the overtaking vessel shall:

1. Indicate her intention by sounding the appropriate signal prescribed by Rule 34(c); and 2. Take steps to permit safe passing.

The vessel being overtaken, if in agreement, shall sound the same signal and may, if specifically agreed to, take steps to permit safe passing. If in doubt, the vessel being overtaken shall sound the doubt/danger signal prescribed by Rule 34(d). 33 CFR §83.09

Critically, this provision does not relieve the overtaking vessel of her obligation under Rule 13. 33 CFR §83.09 The overtaking vessel remains the give-way vessel throughout the maneuver regardless of any signals exchanged.

Bends and obstructions

A vessel nearing a bend or an area of a narrow channel or fairway where other vessels may be obscured by an intervening obstruction shall navigate with particular alertness and caution and shall sound the appropriate signal prescribed by Rule 34(e). 33 CFR §83.09

Anchoring

Any vessel shall, if the circumstances of the case admit, avoid anchoring in a narrow channel. 33 CFR §83.09

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Why It Matters on the Exam

Rule 9 overrides Rule 18 — but only in specific ways

Rule 18 (Responsibilities Between Vessels) opens with the phrase "Except where Rules 9, 10, and 13 otherwise require." 33 CFR §83.18 This means the normal pecking order — power-driven vessel gives way to sailing vessel, fishing vessel, RAM, NUC — can be displaced by Rule 9. A sailing vessel or a vessel engaged in fishing that is less than 20 meters in length must not impede a deep-draft vessel confined to the channel, even though Rule 18 would ordinarily give those vessels stand-on status. 33 CFR §83.09

Exam writers exploit this interaction heavily. A question may describe a 15-meter sailing vessel and a 200-meter tanker in a narrow channel and ask which vessel must give way. The answer turns on Rule 9, not Rule 18.

Rules 11–18 apply only to vessels in sight of one another

Rules 11 through 18 apply to vessels in sight of one another. 33 CFR §83.11 Rule 9, however, is not limited to that condition — its obligations (starboard-side keeping, not impeding, avoiding anchoring) apply regardless of visibility. This distinction matters when a question involves restricted visibility in a narrow channel.

The downbound/upbound rule is Inland-only

The right-of-way of a downbound vessel with a following current applies only on the Great Lakes, Western Rivers, and Secretary-designated waters under the Inland Rules. 33 CFR §83.09 It does not exist under the International Regulations. If a question specifies open ocean or waters seaward of the COLREG demarcation lines, this provision does not apply.

Application of the Inland Rules

The Inland Rules apply to all vessels upon the inland waters of the United States, and to vessels of the United States on the Canadian waters of the Great Lakes to the extent there is no conflict with Canadian law. 33 CFR §83.01 Operators of self-propelled vessels 12 meters or more in length are required to carry and maintain for ready reference a copy of these Rules. 33 CFR §83.01 Vessels of 39.4 feet (12 meters) or more operating shoreward of the COLREG Demarcation Lines must also carry a copy of the Inland Navigation Rules under 46 CFR. 46 CFR §28.225

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Common Pitfalls

1. Confusing "shall not impede" with "keep out of the way." These are not the same obligation. "Shall not impede" requires the burdened vessel to act early enough that the privileged vessel never needs to take avoiding action. A vessel that waits until a close-quarters situation develops and then yields has already violated the rule.

2. Forgetting that the overtaking vessel remains bound by Rule 13. Exchanging overtaking signals under Rule 9(e) does not transfer give-way status to the vessel being overtaken. The overtaking vessel retains her obligation to keep clear throughout the maneuver. 33 CFR §83.09

3. Applying the downbound right-of-way rule to all inland waters. The downbound/upbound provision applies only on the Great Lakes, Western Rivers, and waters specified by the Secretary — not every inland waterway. 33 CFR §83.09 Misapplying it to a tidal river or harbor not designated by the Secretary is a common error.

4. Assuming Rule 18's hierarchy is absolute. Rule 18 is explicitly subordinate to Rules 9, 10, and 13. 33 CFR §83.18 A fishing vessel in a narrow channel does not have the right to impede a vessel confined to that channel simply because Rule 18 would normally give fishing vessels stand-on status.

5. Thinking a sailing vessel is exempt from Rule 9. A sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway. 33 CFR §83.09 Sail does not confer immunity from Rule 9 obligations.

6. Overlooking the bend signal requirement. Candidates often remember the starboard-side rule but forget that a vessel approaching a blind bend must sound the signal prescribed by Rule 34(e) and navigate with particular alertness and caution. 33 CFR §83.09

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Quick Check

Q1 — You are operating a 12-meter sailing vessel in a narrow channel. A 180-meter cargo vessel that can safely navigate only within the channel is approaching from astern. What is your obligation under Rule 9?

You shall not impede the passage of the cargo vessel. A sailing vessel shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway, regardless of the normal stand-on status sailing vessels enjoy under Rule 18. 33 CFR §83.09

Q2 — On the Mississippi River (a Western River), two power-driven vessels are meeting in a narrow channel. Vessel A is downbound with a following current; Vessel B is upbound. Which vessel has the right-of-way, and what must each vessel do?

Vessel A (downbound with a following current) has the right-of-way. Vessel A shall propose the manner and place of passage and initiate the maneuvering signals prescribed by Rule 34(a)(i). Vessel B (upbound against the current) shall hold as necessary to permit safe passing. 33 CFR §83.09

Q3 — A power-driven vessel intends to overtake another power-driven vessel in a narrow channel. The overtaking vessel sounds the appropriate Rule 34(c) signal and the vessel being overtaken agrees. Is the overtaking vessel now relieved of her give-way obligation?

No. Rule 9(e)(ii) expressly states that this provision does not relieve the overtaking vessel of her obligation under Rule 13. The overtaking vessel remains the give-way vessel throughout the maneuver. 33 CFR §83.09

Q4 — A vessel engaged in fishing is working gear inside a narrow channel. A tug with tow that can safely navigate only within the channel is approaching. What does Rule 9 require of the fishing vessel?

A vessel engaged in fishing shall not impede the passage of any other vessel navigating within a narrow channel or fairway. The fishing vessel must take early action to ensure it does not obstruct the tug and tow. 33 CFR §83.09

Q5 — Your vessel is approaching a bend in a narrow channel where other vessels may be obscured. What actions does Rule 9 require?

Your vessel shall navigate with particular alertness and caution and shall sound the appropriate signal prescribed by Rule 34(e). 33 CFR §83.09

Q6 — Does the downbound right-of-way provision of Inland Rule 9 apply on a tidal river that has not been designated by the Secretary?

No. The downbound/upbound right-of-way provision applies only on the Great Lakes, Western Rivers, and waters specifically designated by the Secretary. A tidal river not so designated is not covered by this provision. 33 CFR §83.09