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100+ Free Asst Eng UFIV Practice Questions

Prepare for the USCG Assistant Engineer Uninspected Fishing Industry Vessels (UFIV) exam with instant access — no signup required.

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2026 Statistics

Key Facts: Asst Eng UFIV Exam

150

Total Questions (Motor Path)

USCG NMC UFIV02 (3 × 50)

70%

Passing Score per Module

USCG NMC UFIV02

50

Questions per Module

USCG NMC UFIV02 Q690/Q692/Q693

3 years / 2/3 motor

Service Requirement

46 CFR 11.530

$240

Typical Original Fee Total

46 CFR 10.219 lower-level

15 ppm

Bilge Oil Discharge Limit

MARPOL Annex I

≥200 GRT

Typical UFIV Vessel Application

46 CFR 11.530

The Assistant Engineer UFIV (NMC code UFIV02) is a U.S. Coast Guard merchant marine engineer endorsement for assistant engineers on uninspected fishing industry vessels. Candidates qualify under 46 CFR 11.530 with three years of engineroom service, two-thirds on motor vessels, generally for vessels of 200 GRT or more (with listed exceptions). The original motor-path exam is modular multiple choice: Q690 Motor Plants (50Q), Q692 Engineering Safety & Environmental Protection (50Q), and Q693 General Subjects (50Q), each requiring 70%. Typical original lower-level fees are $100 evaluation + $95 exam + $45 issuance ($240) under 46 CFR 10.219. Content emphasizes fishing-vessel and workboat diesel engineering, MARPOL bilge and pollution rules, and auxiliaries such as pumps, refrigeration, hydraulics, and electrical systems.

Sample Asst Eng UFIV Practice Questions

Try these sample questions to test your Asst Eng UFIV exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.

1On a marine diesel engine, what is the primary purpose of fuel injection timing?
A.To control jacket-water temperature
B.To regulate turbocharger boost pressure
C.To set the crank angle at which fuel begins to burn so peak pressure occurs shortly after top dead center
D.To set day-tank fuel viscosity
Explanation: Injection timing fixes the crank position where injection (and combustion) begins; correct timing places peak cylinder pressure just after TDC for useful work without excessive stress.
2A diesel engine will not rotate when starting air is admitted, although air pressure is normal. The most likely cause is that the:
A.Cooling expansion tank is slightly low
B.Turning (jacking) gear is still engaged
C.Fuel oil is too cold for the day-tank heater setpoint
D.Crankcase oil level is slightly above the high mark
Explanation: An engaged turning gear locks the engine and prevents rotation on starting air; interlocks normally block air admission, so an engaged gear or failed interlock is classic.
3In a four-stroke-cycle diesel engine, how many crankshaft revolutions complete one full cycle in each cylinder?
A.One revolution (360°)
B.One-half revolution (180°)
C.Three revolutions (1080°)
D.Two revolutions (720°)
Explanation: A four-stroke cycle completes intake, compression, power, and exhaust over two crankshaft revolutions (720°).
4What is the chief function of scavenging in a two-stroke marine diesel?
A.To inject fuel at the correct crank angle
B.To remove burned gases from the cylinder and replace them with fresh air
C.To lubricate the wrist pin
D.To cool the injector tip between firings
Explanation: Scavenging uses pressurized fresh air to expel exhaust and fill the cylinder with clean air because a two-stroke has no separate exhaust stroke.
5Many fishing vessels cool the main engine with a keel cooler instead of a raw-water heat exchanger because a keel cooler:
A.Circulates seawater directly through the engine jackets
B.Keeps engine coolant in a closed loop and rejects heat through external piping in contact with the sea
C.Removes the need for any coolant circulating pump
D.Eliminates the need for corrosion inhibitor in the coolant
Explanation: A keel cooler is external piping welded to or hung on the hull; jacket coolant circulates through it and gives up heat to the surrounding water without raw water ever entering the engine. That removes raw-water pump impellers, strainers, and internal seawater fouling, which matters on boats working in debris-laden, silty, or icy water.
6On a four-stroke marine diesel, the camshaft is driven at:
A.Twice crankshaft speed
B.Half crankshaft speed
C.The same speed as the crankshaft
D.A speed varied by the governor with load
Explanation: A four-stroke cycle occupies two crankshaft revolutions, and each valve and fuel cam must act once per cycle, so the timing gears turn the camshaft once for every two turns of the crankshaft. On a two-stroke the camshaft runs at crankshaft speed because the cycle completes in one revolution.
7Blue or blue-grey exhaust smoke from a marine diesel typically indicates:
A.Overfueling with clean injectors
B.Burning of lubricating oil in the combustion space
C.Normal complete combustion
D.Coolant entering the combustion chamber
Explanation: Blue/grey smoke usually means lube oil is reaching the combustion space via worn rings, valve guides, or cylinder lubrication overfeed.
8On a fishing-vessel main diesel, the fuel oil viscosity controller is primarily intended to:
A.Raise fuel heating value
B.Keep fuel at the viscosity required for proper atomization at the injectors
C.Remove water from the day tank
D.Increase cetane number
Explanation: Viscosity heaters/controllers hold fuel at the viscosity needed for correct atomization and injection system protection.
9What is the primary purpose of a charge-air (after) cooler on a turbocharged marine diesel?
A.To heat scavenging air for better vaporization
B.To cool compressed intake air so denser air enters the cylinders
C.To cool jacket water leaving the engine
D.To condense exhaust for muffling
Explanation: Cooling compressed charge air increases density and mass of oxygen per cycle, improving power and reducing thermal stress.
10If turbocharger compressor fouling reduces airflow on a workboat diesel under load, the engineer should expect:
A.Lower exhaust temperature and white smoke only
B.Higher exhaust temperature and black smoke from incomplete combustion
C.Immediate crankcase explosion
D.Automatic increase in governor setpoint only
Explanation: Restricted air mass causes over-rich mixture under load: exhaust temperature rises and black smoke appears from incomplete combustion.

About the Asst Eng UFIV Exam

The USCG Assistant Engineer of Uninspected Fishing Industry Vessels endorsement (NMC exam code UFIV02) authorizes service as assistant engineer on uninspected fishing industry vessels. Under 46 CFR 11.530, the endorsement generally applies to fishing industry vessels of 200 gross register tons or more, with exceptions for wooden vessels of primitive build, unrigged vessels, and vessels under 200 GRT. Qualification requires three years of engineroom service, of which two-thirds must have been on motor vessels. The written examination for the original motor path comprises three multiple-choice modules—Q690 Motor Plants, Q692 Engineering Safety & Environmental Protection, and Q693 General Subjects—each 50 questions with a 70 percent passing score. An orally assisted examination option exists under 46 CFR 11.530(f).

Assessment

UFIV02 modular REC battery for original motor path: Q690 Motor Plants (50, 70%), Q692 Engineering Safety & Environmental Protection (50, 70%), Q693 General Subjects (50, 70%). Total 150 multiple-choice questions. An orally assisted examination option is available under 46 CFR 11.530(f) when eligible.

Time Limit

Up to 3.5 hours per module

Passing Score

70% on each module

Exam Fee

$95 exam fee; $240 total typical original lower-level application ($100 evaluation + $95 exam + $45 issuance) (U.S. Coast Guard National Maritime Center (NMC) / Regional Exam Centers)

Asst Eng UFIV Exam Content Outline

40%

Motor Plants (Q690)

Diesel engine fundamentals and two- and four-stroke cycles on fishing and workboat plants, fuel injection and timing, fuel viscosity and heating, turbocharging, scavenging and charge-air cooling, governors, cooling and lubrication systems, starting air safety, reduction gear and controllable-pitch propeller concepts, and casualty control including hot bearings, oil mist, and crankcase explosions

30%

Engineering Safety & Environmental Protection (Q692)

Fire triangle and fire classes, portable extinguishers and fixed CO2/foam systems, SCBA and enclosed-space entry, lockout/tagout, damage control and dewatering, MARPOL 15 ppm machinery-space bilge discharge and the Oil Record Book, OPA 90 spill response, garbage Annex V (plastics prohibition), and hazardous materials/SDS on commercial fishing vessels

30%

General Subjects (Q693)

Centrifugal and positive-displacement pumps, priming and cavitation, fuel and lube oil purifiers, oily water separators, refrigeration and fish-hold cooling, hydraulics and deck machinery, AC generation and motor controllers, heat exchangers and zinc anodes, valves and piping, and engineer watchstanding duties

How to Pass the Asst Eng UFIV Exam

What You Need to Know

  • Passing score: 70% on each module
  • Assessment: UFIV02 modular REC battery for original motor path: Q690 Motor Plants (50, 70%), Q692 Engineering Safety & Environmental Protection (50, 70%), Q693 General Subjects (50, 70%). Total 150 multiple-choice questions. An orally assisted examination option is available under 46 CFR 11.530(f) when eligible.
  • Time limit: Up to 3.5 hours per module
  • Exam fee: $95 exam fee; $240 total typical original lower-level application ($100 evaluation + $95 exam + $45 issuance)

Keys to Passing

  • Work through all 100 available questions
  • Review every answer and explanation
  • Track weak areas and revisit them
  • Use our AI tutor for tough concepts

Asst Eng UFIV Study Tips from Top Performers

1Treat each module as a separate 50-question test at 70% — drill motor plants, safety/environmental, and general subjects as independent passes
2Master diesel casualty control: on suspected hot bearing or oil mist, slow or stop the engine and keep crankcase doors shut to avoid a violent secondary crankcase explosion
3Memorize the MARPOL 15 ppm machinery-space bilge limit, Oil Record Book Part I entries, and that plastics may never be discharged under Annex V
4Know fire classes (A combustibles, B flammable liquids, C electrical, D metals) and that CO2 total-flooding requires the space evacuated, sealed, and ventilation secured
5Understand 46 CFR 11.530 service: 3 years engineroom, two-thirds on motor vessels, and the ≥200 GRT fishing-industry application with listed exceptions
6Drill pumps (NPSH/cavitation), refrigeration for fish-hold cooling, hydraulics for winches and deck gear, and basic generator paralleling for general subjects
7Practice fuel viscosity control, injection timing, turbocharger fouling, and jacket-water temperature regulation for fishing-vessel diesels
8Simulate 50-question timed sets within 3.5-hour module windows before your REC appointment

Frequently Asked Questions

What does the Assistant Engineer UFIV endorsement authorize?

The USCG Assistant Engineer of Uninspected Fishing Industry Vessels endorsement authorizes service as assistant engineer on uninspected fishing industry vessels under 46 CFR 11.530. The endorsement generally applies to fishing industry vessels of 200 gross register tons or more, with exceptions for wooden vessels of primitive build, unrigged vessels, and vessels of less than 200 GRT.

How is the UFIV02 Assistant Engineer exam structured?

The original motor-path exam (NMC code UFIV02) is delivered as three separate multiple-choice modules: Q690 Motor Plants (50 questions), Q692 Engineering Safety & Environmental Protection (50 questions), and Q693 General Subjects (50 questions). Each module requires a 70 percent passing score and is graded independently, for a total of 150 questions.

What experience is required under 46 CFR 11.530?

Under 46 CFR 11.530, applicants for Assistant Engineer of Uninspected Fishing Industry Vessels must document three years of service in the engineroom of vessels, of which two-thirds of the required service must have been on motor vessels, plus the medical, drug-testing, and MMC documentation required for credential issuance.

Is an orally assisted exam available?

Yes. 46 CFR 11.530(f) provides for an orally assisted examination option for eligible Assistant Engineer UFIV applicants. Confirm current eligibility and procedures with the National Maritime Center and your Regional Exam Center when you apply.

What is the passing score on each UFIV02 module?

Each module is graded independently and requires a minimum passing score of 70 percent. Candidates may take and pass the modules separately, and only the failed module(s) must be retaken if a candidate does not pass the full set.

How much does the Assistant Engineer UFIV exam cost?

For a typical original lower-level officer endorsement under 46 CFR 10.219, expect about $100 evaluation, $95 examination, and $45 issuance ($240 total). Fees are paid through Pay.gov. Confirm current amounts on the NMC fees page before applying.

What topics are emphasized for fishing-vessel engineers?

UFIV assistant engineer candidates should master marine diesel plants typical of fishing and workboats, machinery-space firefighting and enclosed-space safety, MARPOL bilge discharge and pollution prevention, and auxiliaries such as pumps, refrigeration for fish holds, hydraulics for deck machinery, and shipboard electrical generation and motor control.

Is this practice bank an official Coast Guard exam?

No. OpenExamPrep provides a FREE English multiple-choice study aid aligned to the UFIV02 Q690, Q692, and Q693 topic areas. Official exams are administered by the Coast Guard at Regional Exam Centers using current NMC banks.