MSC Circulars
Maritime Safety Committee (MSC) Circulars are non-binding guidance documents issued by the IMO's principal safety body. Unlike Resolutions (which can be adopted as amendments to conventions and become binding), Circulars are recommendations to Member States, industry, and mariners. However, many Circulars are directly referenced within SOLAS, STCW, ISM Code, ISPS Code, and other conventions — so what is "guidance" in name becomes effectively mandatory in practice. Every Master, Chief Officer, and DPA working under a modern SMS must be able to identify + cite the relevant MSC Circulars.
Circular numbering
- MSC.1/Circ.XXXX. Standard MSC Circular. Format: "MSC.1/Circ.1228 — Revised Guidance to the Master". Numbers are strictly sequential across Committee sessions.
- MSC.2/Circ.XXXX. Confidential or restricted MSC Circulars (relatively rare — mostly security-related).
- MSC-MEPC.X/Circ.XXXX. Joint MSC-MEPC Circulars where safety + environmental protection overlap. Example: MSC-MEPC.5/Circ.13 on integrated management-system elements.
- MSC/Circ.XXXX. Legacy format used pre-2005. Still cited when the source document has not been superseded.
Notable operationally-cited MSC Circulars (25)
Full source: imo.org/en/OurWork/Circulars. Curated below for operational relevance.
| Circular | Subject | Cross-link |
|---|---|---|
| MSC.1/Circ.1228 (2007) | Revised guidance to the Master for avoiding dangerous situations in adverse weather + sea conditions | Parametric roll |
| MSC.1/Circ.1353 (2010) | Revised guidelines on IMO Model Course 3.19 Ship Security Officer | ISPS Code |
| MSC.1/Circ.1370 (2010) | Revised guidelines on early implementation of the annexed regulations of the Maritime Labour Convention | MLC 2006 |
| MSC.1/Circ.1400 (2011) | Interim recommendations on stability regulations for cruise passenger ships (post-Costa Concordia) | Costa Concordia |
| MSC.1/Circ.1420 (2012) | Guidelines for the development of a maritime cyber risk management framework | Cyber security |
| MSC.1/Circ.1481 (2014) | Casualty Investigation Code — practical guidance for flag-state investigators | Accident investigation |
| MSC.1/Circ.1503 (2015) | Revised guidelines for the ISM Code + implementation guidance | ISM Code |
| MSC.1/Circ.1519 (2015) | Guidelines on cyber security onboard ships | Cyber security |
| MSC.1/Circ.1526 (2016) | Unified interpretation of provisions of SOLAS chapter III relating to means of escape | SOLAS Chapter III |
| MSC.1/Circ.1580 (2017) | Revised guidelines on the design + inspection + maintenance of accommodation ladders + gangways | Boarding arrangement safety |
| MSC-MEPC.5/Circ.13 (2018) | Guidelines for integration + rationalisation of ISM Code + Marine Environment Protection SMS elements | ISM Code integration |
| MSC.1/Circ.1591 (2018) | Guidelines on fire safety in enclosed cargo spaces | Enclosed-space safety |
| MSC.1/Circ.1598 (2019) | Guidelines on fatigue — updates to Res. A.1108(29) fatigue-management framework | Hours of rest |
| MSC.1/Circ.1602 (2019) | Enclosed-space entry safety — atmosphere testing + rescue procedure guidance | Enclosed-space entry |
| MSC-MEPC.7/Circ.11 (2020) | Recommended framework of protocols for ensuring safe ship crew changes during a pandemic | Pandemic preparedness |
| MSC.1/Circ.1620 (2020) | Guidelines for the acceptance of manufacturer-produced life-saving appliances following COVID-19 disruption | Pandemic preparedness |
| MSC.1/Circ.1621 (2020) | Interim guidelines for the safety of ships using methanol as fuel | Methanol + ammonia dual-fuel |
| MSC.1/Circ.1626 (2020) | Best Management Practice (BMP) updates for anti-piracy transits | Piracy incidents |
| MSC.1/Circ.1636 (2020) | Recommended framework of protocols for ensuring safe ship crew changes + travel during COVID-19 (heavily updated 2020-2022) | Crew change during health emergencies |
| MSC.1/Circ.1638 (2021) | Outcome of the joint MSC/MEPC/LEG working group on maritime autonomous surface ships (MASS) | MASS Code + IACS UR |
| MSC.1/Circ.1647 (2022) | Guidelines on maritime cyber risk management update — post NotPetya + DP World learning integration | Marine cyber incidents |
| MSC.1/Circ.1651 (2024) | Cyber-security updates for the OT/IT boundary — IACS UR E26/E27 alignment | IACS UR E26/E27 |
| MSC.1/Circ.1652 (2024) | MASS Code development progress + interim guidance | MASS Code |
| MSC.1/Circ.1667 (2024) | Emergency preparedness for CIC 2026 — Paris + Tokyo MoU joint campaign | PSC CIC tracker |
| MSC.1/Circ.1687 (2024) | Interim guidelines for ships using ammonia as fuel — toxicity + release-response focus | Ammonia dual-fuel |
Finding + citing an MSC Circular
- Full IMO catalogue is at imo.org/en/OurWork/Circulars. IMODOCS provides access to signed-in Member State delegates; the IMO public site provides most of the current Circulars.
- Class-society websites (DNV, LR, ABS, ClassNK) typically maintain search-friendly Circular catalogues covering their notational + statutory work.
- For SMS + Master's reference: the ISF SIRB (Ship Master's Instructional Reference Book) and ISF ShipMaster consolidate operationally-relevant Circulars.
- Citation format: "MSC.1/Circ.1228 (2007) — Revised Guidance to the Master". Include the year for clarity if the topic has multiple Circulars.
See also
- · MEPC Resolutions — parallel environmental-side instrument.
- · IACS Unified Requirements.
- · Convention ratifications matrix.
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