Overtaking Situations (Rule 13)

Introduction

The third "in-sight" encounter is Overtaking, governed by Rule 13 - Overtaking. This rule is legally unique because it acts as a "trump card," overriding most other steering rules, including the vessel hierarchy.

Defining an Overtaking Situation (Rule 13)

An overtaking situation is defined by the vessel's approach angle.

Rule 13(b) - Recognition

"A vessel shall be deemed to be overtaking when coming up with another vessel from a direction more than 22.5 degrees abaft her beam"

This sector (135° wide) is the exact arc of the vessel's sternlight.

Daytime Recognition: You are approaching another vessel from behind.

Night-time Recognition: You "would be able to see only the sternlight (a white light) of that vessel but neither of her sidelights (red or green)".

Critical Distinction: If you can see either sidelight, it is not an overtaking situation; it is a crossing situation (Rule 15).

The "Trump Card" - Responsibilities of the Vessels

The responsibilities in an overtaking situation are the simplest and most absolute of all the rules.

Rule 13(a) - The "Trump Card" Clause

"Notwithstanding anything contained in Rules 4 through 18, any vessel overtaking any other shall keep out of the way of the vessel being overtaken."

The phrase "Notwithstanding..." is a powerful legal term. It means that Rule 13 overrides all other in-sight rules, including the vessel hierarchy of Rule 18.

What This Means in Practice

• A sailboat overtaking a powerboat is the give-way vessel
• A vessel engaged in fishing (with privilege over a powerboat) overtaking a powerboat is the give-way vessel
• A massive container ship overtaking a small recreational boat is the give-way vessel

The action of overtaking makes a vessel the give-way vessel, regardless of its size, type, or privilege.

The vessel being overtaken is the stand-on vessel and is required by Rule 17 to maintain its course and speed.

The "No-Escape" Clauses

Rule 13 is written to be inescapable. It provides two clauses to close any legal loopholes.

Rule 13(c) - The Rule of Doubt

"When a vessel is in any doubt as to whether she is overtaking another, she shall assume that this is the case and act accordingly"

Analysis: If you are near the 22.5-degree boundary and are unsure if it's a crossing or overtaking situation, you must assume you are overtaking and act as the give-way vessel.

Rule 13(d) - The "Once Overtaking, Always Overtaking" Rule

"Any subsequent alteration of the bearing... shall not make the overtaking vessel a crossing vessel... or relieve her of the duty... until she is finally past and clear"

Analysis: This prevents a fast vessel from "gaming the system." A give-way overtaking vessel cannot pull up alongside the other vessel, enter its "crossing" sector, and then claim to be the stand-on vessel in a new crossing situation.

The duty to keep clear persists for the entire duration of the maneuver, from the initial approach until the overtaking vessel is completely past and no longer poses any risk.

Overtaking in a Narrow Channel (Rule 9(e))

A narrow channel presents a special case for overtaking. Because the channel is restricted, the vessel being overtaken often "has to take action to permit safe passing," (e.g., by slowing down or moving to the very edge of the channel).

Because this requires a coordinated, two-vessel maneuver, both International and Inland Rules require the use of sound signals in this specific situation.

CRITICAL DIFFERENCE: Overtaking Sound Signals (Rule 34(c))

While both systems require signals in a narrow channel, the signals themselves are dangerously different.

Inland Rules: Proposal & Agreement

The signals are the same "intent" signals used for head-on and crossing:

Proposal (Overtaking Vessel):

• One short blast (•): "I intend to overtake you on your starboard side"
• Two short blasts (••): "I intend to overtake you on your port side"

Reply (Overtaken Vessel):

• Agreement: Sound the same signal (• or ••)
• Doubt/Danger: Sound the danger signal (five short blasts)

International Rules (Narrow Channel Only): Proposal & Agreement

The signals are completely different and unique to this situation:

Proposal (Overtaking Vessel):

• Two prolonged, one short (- - •): "I intend to overtake you on your starboard side"
• Two prolonged, two short (- - ••): "I intend to overtake you on your port side"

Reply (Overtaken Vessel):

• Agreement: Sound one prolonged, one short, one prolonged, one short (- • - •)
• Doubt/Danger: Sound the danger signal (five short blasts)

The Dangerous Trap

This difference is a significant legal trap. A mariner sounding two short blasts (••) in the Inland waters of the Houston Ship Channel is (correctly) proposing a port-side pass.

That same mariner sounding two short blasts (••) in the International waters of the English Channel is (incorrectly, but legally) stating "I am altering my course to port," which could be a catastrophic, unannounced maneuver with no agreement required.

You MUST know which side of the COLREGS Demarcation Line you are on.

Case Study in Failure: Utopia IV / Tropic Breeze

On December 23, 2021, the 163-foot motor yacht Utopia IV was transiting at high speed in the Bahamas when it collided with and sank the 250-foot tanker Tropic Breeze.

The Situation

A classic overtaking situation. Utopia IV was coming up from astern of the Tropic Breeze.

The Failures

Give-Way Vessel (Rule 13): The Utopia IV had the absolute, "notwithstanding" duty to keep clear.

Stand-On Vessel (Rule 17): The Tropic Breeze had the duty to maintain course and speed.

Probable Cause

The NTSB determined the probable cause was "the Utopia IV's wheelhouse crew not maintaining a proper lookout and therefore not identifying the tank vessel they were overtaking".

Analysis

This accident is a staggering failure of the most basic rules. The overtaking vessel, with the 100% burden of responsibility, failed to even see the 250-foot tanker it was about to hit.

This highlights that Rule 13 (Overtaking) is completely dependent on Rule 5 (Lookout) and Rule 7 (Risk Assessment).

The NTSB also noted that the Tropic Breeze crew (the stand-on vessel) also failed to maintain a proper lookout, which prevented them from recognizing the danger and taking their own required "Phase 3" action under Rule 17(b).

Key Takeaways

• Overtaking defined as approaching from more than 22.5° abaft beam (sternlight sector)
• Night recognition: See ONLY white sternlight, no red or green = overtaking
• Rule 13(a) "trump card": Overtaking vessel ALWAYS give-way, notwithstanding Rules 4-18
• Overrides vessel hierarchy - sailboat overtaking powerboat is give-way
• Rule 13(c) rule of doubt: If unsure if overtaking, assume you are
• Rule 13(d) "once overtaking, always overtaking": Duty persists until finally past and clear
• Narrow channel overtaking requires sound signals in BOTH rule sets
• CRITICAL SIGNAL DIFFERENCE:
  • Inland: • = starboard pass, •• = port pass (same as intent signals)
  • International: - - • = starboard pass, - - •• = port pass
  • International agreement: - • - •
• Using wrong signal set can cause catastrophic misunderstanding
• Utopia IV case: Overtaking vessel failed basic lookout, sank vessel it couldn't see