USCG Cheat Sheet 2026

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

1. In a refrigeration system, what is the role of the expansion valve? → Reduces refrigerant pressure to cause it to cool and absorb heat
2. Which of the following statements about Fireman's attire is TRUE under the laws for cargo vessels? → Each fireman's outfit shall contain a flame safety lamp of an approved type
3. What does SAR datum mean? → The most probable position of a missing vessel or person, accounting for drift and leeway
4. After removing someone from an electrical source who has been rendered unconscious by electric shock, you should _______. → Determine if he is breathing
5. What is the purpose of a 'coffin plate' in a marine boiler? → A reinforcing plate used at the junction of the furnace and boiler shell
6. What does 'securing cargo' involve? → Using lashings, blocking, and bracing to prevent cargo movement during the voyage
7. What is the purpose of the fire main system aboard a vessel? → To distribute seawater under pressure to fire hoses and hydrants throughout the vessel
8. What is the primary purpose of a ship's oily water separator (OWS)? → To separate oil from bilge water before discharge overboard
9. The sizing of tubing is ____. → nominal outside diameter
10. What is a 'fire party' on a vessel? → A designated team of trained crew members responsible for fighting fires
11. When fighting a fire in an enclosed space, what is the primary personal safety concern? → Oxygen depletion and toxic smoke inhalation
12. Which immersion suit feature is most critical for survival in cold water? → Thermal insulation to prevent hypothermia
13. The general by-products of oxidation caused by hydraulic il water contamination are ____. → gums, varnishes, and acids
14. What is the function of a 'stern tube' on a vessel? → Houses the propeller shaft where it passes through the hull
15. What is the recommended immediate action when a person falls overboard? → Throw a life ring, shout 'man overboard,' alert the crew, and keep the person in sight
16. What is a 'man overboard' (MOB) buoy used for? → Marking the location of a person in the water to assist in recovery
17. Which regulation requires vessels over 400 GT to have an approved Sewage Treatment Plant or holding tank? → MARPOL Annex IV
18. What is the primary SAR coordination agency in the U.S.? → The U.S. Coast Guard
19. Under the Inland Rules, a white light visible all around the horizon is required for which vessel? → A vessel less than 7 meters at anchor
20. What does the term 'MARPOL' refer to in marine engineering? → Marine Pollution Prevention Regulations
21. What are the three elements of the fire triangle? → Fuel, heat, and oxygen
22. Before activating a fixed CO2 system in the engine room, what must be done first? → Ensure all personnel have evacuated the space and close all ventilation
23. What is a 'Vessel Response Plan' (VRP) required to address? → Procedures for responding to a worst-case oil spill scenario
24. A power-driven vessel less than 50 meters may not show which light combination? → A tricolor lantern at the masthead
25. Which of the following best describes a striker or double plate's function? → Provides landing surface for the sounding bob of a tank sounding tap
26. What does a 'load cell' measure in marine engineering applications? → Force or weight applied to a structural member
27. Which VHF channel is designated exclusively for Digital Selective Calling (DSC) distress alerts? → Channel 70
28. ____ determines how the free surface affects initial stability. → the dimensions of the liquid surface and the vessel's displacement
29. Which type of breathing apparatus is required for fighting fires in enclosed spaces? → A self-contained breathing apparatus (SCBA)
30. What is the international distress, safety, and calling frequency on VHF radio? → Channel 16