33 CFR 155.380: Oily water separator and bilge alarm approval
Last reviewed: October 14, 2026
This section sets which approvals oily water separating equipment and bilge alarms must hold. It also covers accuracy checks, crew familiarization and maintenance records. U.S. inspected ships must use equipment approved under 46 CFR 162.050.
Applies toIt applies to U.S. inspected ships, U.S. uninspected ships and foreign ships that have oily water separating equipment and bilge alarms.
What it says
On U.S. inspected ships, oily water separating equipment and bilge alarms must be approved under 46 CFR 162.050.
33 CFR 155.380(a)“On U.S. inspected ships, oily water separating equipment and bilge alarms must be approved under 46 CFR 162.050.”
On U.S. uninspected ships and foreign ships, this equipment must be approved under either 46 CFR 162.050 or MARPOL 73/78 Annex I.
33 CFR 155.380(b)“On U.S. uninspected ships and foreign ships, oily water separating equipment and bilge alarms must be approved under either 46 CFR 162.050 or MARPOL 73/78 Annex I.”
A ship required to have a bilge alarm may defer installment and use a previously installed bilge monitor, if the monitor met Coast Guard approval requirements when installed and allows no more than a 15 ppm oil content in water discharge.
33 CFR 155.380(c)“may defer installment and use a previously installed bilge monitor provided the bilge monitor met Coast Guard approval requirements at the time of its installation and it does not allow more than a 15 ppm oil content in water discharge.”
Bilge alarm accuracy must be checked at IOPP Certificate renewal surveys according to the manufacturer's instructions, or the unit may be replaced by a calibrated bilge alarm.
33 CFR 155.380(d)“The accuracy of the bilge alarms must be checked at IOPP Certificate renewal surveys according to the manufacturer's instructions. Alternatively, the unit may be replaced by a calibrated bilge alarm.”
Only the manufacturer or persons authorized by the manufacturer can do the accuracy checks.
33 CFR 155.380(d)“The accuracy checks can only be done by the manufacturer or persons authorized by the manufacturer.”
Ship staff training must include familiarization in the operation and maintenance of the equipment.
33 CFR 155.380(e)“Ship staff training must include familiarization in the operation and maintenance of the equipment.”
The manufacturer must clearly define routine maintenance in the operating and maintenance manuals, and all routine and repair maintenance must be recorded.
33 CFR 155.380(f)“must be clearly defined by the manufacturer in the associated operating and maintenance manuals. All routine and repair maintenance must be recorded.”
Common questions
What approval must oily water separating equipment have on a U.S. inspected ship?
It must be approved under 46 CFR 162.050.
“On U.S. inspected ships, oily water separating equipment and bilge alarms must be approved under 46 CFR 162.050.”
Can a foreign ship use MARPOL-approved oily water separating equipment?
Yes. Foreign ships may use equipment approved under either 46 CFR 162.050 or MARPOL 73/78 Annex I.
“On U.S. uninspected ships and foreign ships, oily water separating equipment and bilge alarms must be approved under either 46 CFR 162.050 or MARPOL 73/78 Annex I.”
Who can check bilge alarm accuracy?
Only the manufacturer or persons authorized by the manufacturer can do the accuracy checks.
“The accuracy checks can only be done by the manufacturer or persons authorized by the manufacturer.”
Where should the bilge alarm calibration certificate be kept?
The certificate, which certifies the date of the last calibration check, should be retained onboard for inspection purposes.
“The calibration certificate for the bilge alarm, which certifies the date of the last calibration check, should be retained onboard for inspection purposes.”
The text of 33 CFR 155.380
Electronic Code of Federal Regulations (eCFR), current as of April 16, 2026 · Read it on eCFR
Oily water separating equipment and bilge alarm approval standards
(a) On U.S. inspected ships, oily water separating equipment and bilge alarms must be approved under 46 CFR 162.050.
(b) On U.S. uninspected ships and foreign ships, oily water separating equipment and bilge alarms must be approved under either 46 CFR 162.050 or MARPOL 73/78 Annex I.
Note to § 155.380(b): A copy of Annex I to the International Convention for the Prevention of Pollution from Ships, 1973 as modified by the Protocol of 1978 relating thereto, as amended (MARPOL 73/78) may be purchased from the International Maritime Organization, Publications Section, 4 Albert Embankment, London SE1 75R, United Kingdom, Telex 23588; see also http://www.imo.org.
(c) A ship that is required to have a bilge alarm may defer installment and use a previously installed bilge monitor provided the bilge monitor met Coast Guard approval requirements at the time of its installation and it does not allow more than a 15 ppm oil content in water discharge.
(d) The accuracy of the bilge alarms must be checked at IOPP Certificate renewal surveys according to the manufacturer's instructions. Alternatively, the unit may be replaced by a calibrated bilge alarm. The calibration certificate for the bilge alarm, which certifies the date of the last calibration check, should be retained onboard for inspection purposes. The accuracy checks can only be done by the manufacturer or persons authorized by the manufacturer.
(e) Ship staff training must include familiarization in the operation and maintenance of the equipment.
(f) The routine maintenance of the oily water separating equipment and the bilge alarm must be clearly defined by the manufacturer in the associated operating and maintenance manuals. All routine and repair maintenance must be recorded.
Sections it refers to
The plain-English explanation on this page was written with AI from the regulation text above and checked automatically before publishing: every quote appears in the text, every number comes from it, and a second model confirmed each statement adds nothing the text doesn't say. Regulation text current as of April 16, 2026. The regulation text governs. RegKnot is not affiliated with the U.S. Coast Guard.