MMC Cheat Sheet 2026

The 30 highest-yield MMC facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. What is the primary purpose of professional standards & ethics in the context of Merchant Mariner Credential? → To ensure consistent quality and professional accountability
2. A vessel steaming at 12 knots on a course of 090°T for 2.5 hours has a DR position how far from the departure point? → 30 nautical miles due east
3. Under 46 CFR, what is required before a vessel's Certificate of Inspection (COI) can be issued? → A successful inspection by the USCG verifying compliance with applicable regulations
4. The intact stability criterion requiring the area under the GZ curve between 0° and 30° heel to be at least 0.055 m·rad is specified by: → IMO Resolution A.749 (IS Code)
5. Under U.S. law, what is the 'Limitation of Liability Act' designed to protect? → Shipowners from unlimited financial ruin following a maritime disaster
6. The double bottom on a ship serves which TWO primary purposes? → Structural strength and watertight reserve buoyancy after grounding
7. What is the primary purpose of a painter line attached to a liferaft? → To secure the liferaft to the vessel until it is fully inflated and boarded
8. Under the IMDG Code, what does a liquid's 'flash point' indicate? → The lowest temperature at which the liquid produces sufficient vapor to ignite
9. When implementing regulatory compliance & legal framework practices, what should a MMC professional prioritize first? → Compliance with established standards and protocols
10. What is the significance of the ship's draft in terms of stability? → A deeper draft can cause the ship to be less stable in shallow waters
11. What action should be taken if a crewmember discovers a fellow crew member showing signs of carbon monoxide (CO) poisoning in an enclosed space? → Call for help, ventilate the space, and do not enter without SCBA
12. Fixed CO2 fire suppression systems in machinery spaces must NOT be activated until: → All personnel are confirmed clear of the space and the space is sealed
13. In Merchant Mariner Credential, what role does quality assurance & continuous improvement play in ensuring client/stakeholder satisfaction? → It builds trust through demonstrated competence and consistency
14. A permeability factor of 0.95 for a cargo hold means: → 95% of the compartment volume can be occupied by floodwater
15. Under the Carriage of Goods by Sea Act (COGSA), what is the carrier's standard limit of liability per package for lost or damaged cargo? → $500 per package or customary freight unit
16. What effect does adding topside weight have on a vessel's stability? → It raises G, reducing GM and worsening stability
17. What is the purpose of the SOLAS (Safety of Life at Sea) Convention? → To set international standards for ship safety
18. Which document must be posted in each crew berthing space outlining emergency duties? → Muster List (Station Bill)
19. A vessel's fire dampers are designed to: → Reduce the spread of smoke and fire through ventilation systems
20. Floodable length at a given position on a vessel is the maximum length of compartment that can be flooded without: → Submerging the margin line
21. What is the MINIMUM number of persons required to lower a survival craft on a USCG-inspected vessel? → One trained crew member
22. What is the purpose of the Maritime Labour Convention (MLC 2006)? → To establish comprehensive rights and employment standards for seafarers worldwide
23. When loading a vessel, what is the primary stability concern the cargo officer must monitor? → Maintaining an adequate metacentric height (GM) throughout loading
24. Which quality improvement method is most applicable to professional standards & ethics in Merchant Mariner Credential? → Plan-Do-Check-Act (PDCA) continuous improvement cycle
25. What does a yellow buoy or marker typically indicate in U.S. waters under the IALA-B system? → A special purpose mark such as a spoil area, anchorage, or traffic separation zone
26. How should a MMC professional handle a situation where regulatory compliance & legal framework protocols conflict with practical constraints? → Document the conflict and seek guidance from appropriate authorities
27. A vessel's DR position differs from an EP (Estimated Position) because the EP: → Accounts for the effects of current, wind, and leeway
28. The term 'deadrise' refers to: → The rise of the bottom plating from the keel toward the bilge
29. On a NOAA nautical chart, a number printed in italics within the water area represents: → A depth in feet below chart datum
30. Hogging stress on a ship's hull occurs when: → The midship section is supported while the bow and stern sag