TL;DR — In an emergency, the firefighting sequence is alert, isolate, shut off fuel/electrical, attack, confirm, then ventilate; damage control priorities are stop flooding, maintain stability, then save the vessel — and an emergency oil discharge is exempt from pollution rules only when all reasonable precautions have been taken to minimize it.
What the Rule Says
Firefighting Sequence
The prescribed firefighting sequence, in order, is: alert the crew, isolate the fire by closing hatches and securing ventilation, shut off fuel and electrical supply to the affected space, attack with the appropriate extinguisher, confirm the fire is extinguished, and then ventilate carefully to prevent re-ignition. USCG Boatswain Manual Ch. 6 §6.3
Each step in that sequence is deliberate. Alerting the crew first ensures that no one is caught unaware and that additional resources are mobilized immediately. Isolating the fire — closing hatches and shutting ventilation — denies the fire its oxygen supply and prevents spread to adjacent spaces. Shutting off fuel and electrical removes the energy source feeding the fire. Only after those preparatory steps is an attack with an extinguisher appropriate. Confirming extinguishment before ventilating is critical: premature ventilation reintroduces oxygen and can cause re-ignition or a backdraft.
Approved Fire Extinguishing Equipment
Where fire extinguishing equipment is required to be of an approved type, it must be approved as provided in 46 CFR chapter I, subchapter Q. A listing of current and formerly approved equipment and materials is maintained online, and each Officer in Charge, Marine Inspection (OCMI) may be contacted for information concerning approved equipment. 33 CFR §175.305
Damage Control Priorities
Damage control on small vessels follows three priorities in strict order: (1) stop the flooding, (2) maintain stability, (3) save the vessel. If priorities one and two cannot be accomplished, the order is to abandon ship. USCG Boatswain Manual Ch. 5 §5.1
The ordering is not arbitrary. A vessel that is flooding but stable can still be worked; a vessel that has lost stability will capsize regardless of whether flooding is controlled. Saving the vessel is subordinate to both, because a vessel that has capsized or sunk cannot be saved in any meaningful operational sense. The abandon-ship decision follows only when both flooding control and stability maintenance have failed.
Emergency Deviations from Navigation Rules
In an emergency, any person may deviate from the rules in 33 CFR Part 164 to the extent necessary to avoid endangering persons, property, or the environment. The sole exception is the requirements of 33 CFR §164.53(b), which remain in force regardless. 33 CFR §164.51
Emergency Oil Discharge Exceptions
The general prohibitions on oil discharge found in 33 CFR §§151.10 and 151.13 do not apply in two specific emergency circumstances. 33 CFR §151.11
First, a discharge of oil or oily mixture is permitted when it is necessary for the purpose of securing the safety of a ship or saving life at sea.
Second, a discharge resulting from damage to a ship or its equipment is exempt, provided that: (i) all reasonable precautions have been taken after the occurrence of the damage or discovery of the discharge for the purpose of preventing or minimizing the discharge; and (ii) the owner or master did not act with intent to cause damage, or recklessly and with knowledge that damage would probably result. Both conditions must be satisfied simultaneously — the precaution requirement and the absence of intentional or reckless conduct.
Oil Spill Response Equipment Standards
Fire and pollution response equipment referenced in 33 CFR Part 155 incorporates by reference a number of recognized standards. For oil spill response, these include ASTM F 631-93 for skimmer performance data, ASTM F 715-95 for coated fabrics used in oil spill control and storage, ASTM F1413-07 and ASTM F1737-07 for dispersant application equipment and its use, and ASTM F1779-08 for reporting visual observations of oil on water. 33 CFR §155.140
For marine firefighting qualifications and incident management, the incorporated standards include NFPA 1001, NFPA 1005, NFPA 1021, NFPA 1405, and NFPA 1561. NFPA 1405, the Guide for Land-Based Fire Fighters Who Respond to Marine Vessel Fires, is incorporated for both §§155.4035 and 155.4050.
Why It Matters on the Exam
OUPV and Master 100 GT written examinations test emergency response in two primary ways: procedural sequence questions and regulatory exception questions.
Procedural sequence questions present the firefighting or damage control steps out of order and ask the candidate to identify the correct sequence or the next correct action. The exam will frequently offer "attack the fire immediately" as a distractor — this is wrong because isolation and fuel/electrical shutoff must precede the attack. Similarly, "ventilate immediately after discharge of the extinguisher" is a trap; ventilation is the final step, performed carefully and only after extinguishment is confirmed. USCG Boatswain Manual Ch. 6 §6.3
For damage control, the exam tests whether candidates know that stability maintenance ranks above saving the vessel. A question may describe a scenario where correcting a list (stability) conflicts with pumping a flooded compartment (stopping flooding) — the answer is always to address flooding first, then stability, then the vessel itself. USCG Boatswain Manual Ch. 5 §5.1
Regulatory exception questions on oil discharge test whether candidates understand that the emergency exception under 33 CFR §151.11 is conditional, not absolute. The exam will present scenarios where a discharge occurred and ask whether the master is liable. The correct analysis requires checking: Was the discharge necessary for ship safety or saving life? If damage-related, were all reasonable precautions taken? Did the owner or master act intentionally or recklessly? All three elements must be evaluated. 33 CFR §151.11
The emergency deviation provision under 33 CFR §164.51 is tested in the context of vessel traffic and navigation rule compliance. Candidates must know that deviation is permitted to the extent necessary — not as a blanket waiver — and that §164.53(b) requirements are explicitly excluded from the deviation authority. 33 CFR §164.51
Fire extinguisher approval questions will ask where approval authority comes from. The answer is 46 CFR chapter I, subchapter Q, and the OCMI is the point of contact for approved equipment information. 33 CFR §175.305
Common Pitfalls
Pitfall 1 — Ventilating too early. Candidates frequently select "ventilate the space" as a step that follows immediately after extinguisher discharge. The correct sequence places ventilation last, and only after extinguishment is confirmed, specifically to prevent re-ignition. USCG Boatswain Manual Ch. 6 §6.3
Pitfall 2 — Attacking the fire before isolating it. The instinct to immediately deploy an extinguisher is wrong procedurally. Hatches must be closed and ventilation secured before attack, or the fire will continue to receive fresh air and may spread.
Pitfall 3 — Inverting damage control priorities. "Save the vessel" sounds like the primary goal, but it is the third priority. Stability is second. Flooding control is first. Candidates who invert these will select wrong answers on scenario-based questions. USCG Boatswain Manual Ch. 5 §5.1
Pitfall 4 — Treating the oil discharge emergency exception as unconditional. The exception under 33 CFR §151.11 for damage-related discharges requires that all reasonable precautions be taken to prevent or minimize the discharge. A master who does nothing after discovering a discharge does not qualify for the exception, even if the discharge originated from damage. 33 CFR §151.11
Pitfall 5 — Assuming intentional or reckless conduct is covered. The damage-related discharge exception explicitly does not apply if the owner or master acted with intent to cause damage, or recklessly and with knowledge that damage would probably result. Recklessness with knowledge defeats the exception entirely.
Pitfall 6 — Confusing fire extinguisher approval authority. Approval is under 46 CFR chapter I, subchapter Q — not 33 CFR, not the OCMI directly. The OCMI provides information about approved equipment but is not the approving authority. 33 CFR §175.305
Quick Check
Q1 — What is the correct order of the firefighting sequence?
Alert the crew → isolate the fire (close hatches, secure ventilation) → shut off fuel and electrical to the affected space → attack with the appropriate extinguisher → confirm extinguished → ventilate carefully to prevent re-ignition. USCG Boatswain Manual Ch. 6 §6.3
Q2 — What are the three damage control priorities in order?
(1) Stop the flooding. (2) Maintain stability. (3) Save the vessel. If priorities one and two fail, abandon ship. USCG Boatswain Manual Ch. 5 §5.1
Q3 — Under what two circumstances does the emergency exception to oil discharge prohibitions apply?
First, when the discharge is necessary to secure the safety of a ship or save life at sea. Second, when the discharge results from damage to the ship or its equipment, provided all reasonable precautions were taken to prevent or minimize the discharge, and provided the owner or master did not act with intent to cause damage or recklessly with knowledge that damage would probably result. 33 CFR §151.11
Q4 — A master discovers a damage-related oil discharge and takes no action to minimize it. Does the emergency exception apply?
No. The exception for damage-related discharges requires that all reasonable precautions be taken after the occurrence of the damage or discovery of the discharge to prevent or minimize it. Inaction after discovery defeats the exception.
Q5 — Under 33 CFR §164.51, may a person deviate from all navigation rules in an emergency?
No. Deviation is permitted to the extent necessary to avoid endangering persons, property, or the environment, but the requirements of §164.53(b) are explicitly excluded and remain in force regardless of the emergency. 33 CFR §164.51
Q6 — What regulatory authority governs approval of fire extinguishing equipment required to be of an approved type?
Approval is governed by 46 CFR chapter I, subchapter Q. Each OCMI may be contacted for information concerning approved equipment. 33 CFR §175.305
Q7 — Why must ventilation be performed carefully and only after extinguishment is confirmed?
Premature ventilation reintroduces oxygen to the affected space, which can cause re-ignition of residual fuel or hot materials. Ventilation is the final step in the firefighting sequence specifically to prevent this outcome.