Examination Practice Questions And

Coast Guard QMED Deck Engineer Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a bilge system on a vessel?
• Provide fresh water to the crew
• Supply fuel to the engines
• Remove water from the lowest part of the ship
• Lubricate machinery

Rationale: The bilge system is designed to collect and pump out

unwanted water from the vessel’s lowest compartments to prevent flooding.

• What is the normal operating pressure range for a typical shipboard

hydraulic system? 1 / 4

• 100–300 psi
• 300–500 psi
• 1000–3000 psi
• 5000–7000 psi

Rationale: Most marine hydraulic systems operate between 1000 and

3000 psi for safe and efficient operation of machinery.

• Which of the following is a primary function of the deck department?
• Engine maintenance
• Cargo operations and ship handling
• Electrical troubleshooting
• Cargo operations and ship handling

Rationale: Deck personnel are responsible for navigation, mooring,

and cargo handling, whereas engine room tasks fall under engineering.

• What is the primary danger of allowing water to accumulate in the

bilge?

• Corrosion
• Stability hazards
• Fire risk
• Fuel contamination

Rationale: Excessive water in the bilge can affect the ship’s stability,

increasing the risk of capsizing.

• Which type of fire extinguisher is suitable for electrical fires?
• Water 2 / 4

• Foam

C. CO₂

D. CO₂

Rationale: CO₂ extinguishers are non-conductive and effectively

smother electrical fires without causing further damage.

6. The function of a relief valve in a steam system is to:

• Increase pressure
• Prevent overpressure
• Measure temperature
• Control fuel flow

Rationale: Relief valves open automatically to release excess pressure

and protect the system from damage or explosion.

• When performing maintenance on a fuel oil transfer system, which

safety precaution is most important?

• Checking fuel viscosity
• Lockout/tagout
• Measuring tank levels
• Cleaning strainers

Rationale: Lockout/tagout ensures that pumps and valves cannot be

activated during maintenance, preventing spills and injuries.

• Which of the following best describes cavitation in a pump?
• Chemical corrosion of pump parts
• Excessive lubrication 3 / 4

• Formation and collapse of vapor bubbles in liquid
• Overheating due to friction

Rationale: Cavitation occurs when vapor bubbles form in low-pressure

zones and collapse, causing damage to pump impellers.

• What is the function of a ship’s draft marks?
• Measure air temperature
• Indicate how deep the ship sits in water
• Monitor bilge levels
• Measure fuel levels

Rationale: Draft marks provide visual reference to ensure proper

loading and stability.

• Which safety device is designed to stop a rotating shaft in an

emergency?

• Safety valve
• Relief valve
• Mechanical coupling shear pin
• Pressure gauge

Rationale: Shear pins in couplings break under excessive load to

protect the shaft and machinery from damage.

• Which type of pump is commonly used for circulating lubricating

oil in marine engines?

• Centrifugal pump
• Gear pump
• / 4