100+ Free Chief Engineer OSV Practice Questions
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Key Facts: Chief Engineer OSV Exam
OSE01
NMC Exam Code
USCG NMC
70%
Passing Score per Module
USCG NMC OSE01
70 questions
Per Exam Module
USCG NMC OSE01
280 questions
Four Modules Combined
USCG NMC OSE01 Q680-Q684
4 years / 1 yr officer / 2 yr QMED
Service Requirement
46 CFR 11.553
~$240
Typical Original Lower-Level Fees
46 CFR 10.219
15 ppm
Bilge Oil Discharge Limit
MARPOL Annex I
Q680-Q684
Exam Modules
USCG NMC OSE01
Chief Engineer-OSV (NMC code OSE01) is a U.S. Coast Guard merchant marine engineer endorsement for chief engineers on offshore supply vessels. Candidates qualify under 46 CFR 11.553 with four years of engineroom service including one year as engineer officer and two years as QMED or equivalent; propulsion power may be limited if less than half the service is on vessels of 4,000 HP or more. The exam is modular multiple choice: Q680 Motor Plants, Q682 General Subjects, Q683 Engineering Safety and Environmental Protection, and Q684 Electricity, Electronics and Control Engineering—each 70 questions with a 70 percent pass mark (about 280 questions total). Typical original lower-level officer MMC fees are about $240 ($100 evaluation + $95 exam + $45 issuance) under 46 CFR 10.219. Content emphasizes management-level diesel casualty control, plant administration, electrical generation and control, and MARPOL/OPA-90 environmental rules.
Sample Chief Engineer OSV Practice Questions
Try these sample questions to test your Chief Engineer OSV exam readiness. Each question includes a detailed explanation. Start the interactive quiz above for the full 100+ question experience with AI tutoring.
1On a medium-speed marine diesel driving an OSV main generator, what is the primary purpose of fuel injection timing?
2A diesel engine will not turn on starting air even though bottle pressure is normal and the air-start distributor appears to cycle. The most likely cause is that the:
3In a four-stroke-cycle diesel, how many crankshaft revolutions complete one full cycle in each cylinder?
4What is the chief function of scavenging on a two-stroke marine diesel?
5The fuel oil service (day) tank on a marine diesel installation is provided to:
6Exhaust valve rotators (rotocaps) are fitted on many four-stroke marine diesels to:
7The primary purpose of a charge-air cooler (intercooler) on a turbocharged diesel is to:
8An engine-driven jacket-water circulating pump is backed up by a motor-driven standby pump mainly so that:
9White smoke during a cold diesel start that clears as the engine warms most often indicates:
10The main purpose of a diesel engine lube-oil filter is to:
About the Chief Engineer OSV Exam
The USCG Chief Engineer of Offshore Supply Vessels (Chief Engineer-OSV) endorsement (NMC exam code OSE01) authorizes service as chief engineer on offshore supply vessels within the propulsion power and route limitations of the endorsement. Under 46 CFR 11.553 it requires four years of engineroom service, including one year as an engineer officer and two years as a Qualified Member of the Engine Department (QMED) or equivalent. If less than 50 percent of that service is on vessels of 4,000 horsepower or more, a propulsion power limitation is applied. The examination is delivered as four multiple-choice modules (Q680, Q682, Q683, Q684) covering motor plants, general subjects at management level, engineering safety and environmental protection, and electricity/electronics/control engineering, each requiring a 70 percent passing score.
Questions
280 scored questions
Time Limit
About 3 hours 30 minutes per module
Passing Score
70% on each module
Exam Fee
About $240 typical original lower-level officer total ($100 evaluation + $95 examination + $45 issuance per 46 CFR 10.219) (U.S. Coast Guard National Maritime Center (NMC))
Chief Engineer OSV Exam Content Outline
Motor Plants (Q680)
Management-level diesel engine fundamentals and two- and four-stroke cycles, fuel injection and timing, turbocharging, scavenging and charge-air cooling, governors, cooling and lubrication systems, starting air safety, mean effective pressure and indicator cards, controllable-pitch propellers, and casualty control including crankcase explosions, oil mist detection, scavenge fires, and hot bearings
General Subjects (Q682)
Management-level auxiliaries and engineering administration: centrifugal and positive-displacement pumps, purifiers and oily water separators, refrigeration, hydraulics and steering gear, heat exchangers, distilling plants, valves and piping, thermodynamics, planned maintenance, spare-parts and bunkering management, and chief engineer watch and casualty organization
Engineering Safety & Environmental Protection (Q683)
Fire triangle and fire classes, fixed CO2 total-flooding and foam systems, SCBA and enclosed-space entry permits, lockout/tagout, damage control, flooding and dewatering, MARPOL 15 ppm bilge discharge and the Oil Record Book, OPA 90, garbage Annex V, hazardous materials/SDS, and OSV industrial-space interface safety
Electricity, Electronics & Control Engineering (Q684)
AC generator frequency and excitation, synchroscope paralleling, real (kW) and reactive (kVAR) load sharing, reverse-power and overload protection, ground detection on ungrounded systems, motor controllers and VFDs, batteries, transformers, rectifiers, PID and feedback control, and engineering plant automation at management level
How to Pass the Chief Engineer OSV Exam
What You Need to Know
- Passing score: 70% on each module
- Exam length: 280 questions
- Time limit: About 3 hours 30 minutes per module
- Exam fee: About $240 typical original lower-level officer total ($100 evaluation + $95 examination + $45 issuance per 46 CFR 10.219)
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
Chief Engineer OSV Study Tips from Top Performers
Frequently Asked Questions
What does the Chief Engineer-OSV endorsement authorize?
The USCG Chief Engineer of Offshore Supply Vessels (Chief Engineer-OSV) endorsement authorizes service as chief engineer on offshore supply vessels within the propulsion power and route limitations stated on the Merchant Mariner Credential, under 46 CFR 11.553.
How is the Chief Engineer-OSV exam structured?
The exam (NMC code OSE01) is delivered as four separate multiple-choice modules: Q680 Motor Plants, Q682 General Subjects, Q683 Engineering Safety and Environmental Protection, and Q684 Electricity, Electronics and Control Engineering. Each module has 70 questions and requires a 70 percent passing score.
How many total questions are on the OSE01 exam?
A candidate who sits all four OSE01 modules takes 280 questions (4 modules × 70 questions). Each module is graded independently at 70 percent.
What experience is required under 46 CFR 11.553?
Chief Engineer-OSV requires four years of service in the engineroom, of which at least one year must be as an engineer officer and at least two years as a Qualified Member of the Engine Department (QMED) or equivalent, plus required training and assessments. If less than 50 percent of the service is on vessels of 4,000 horsepower or more, a propulsion power limitation is applied.
What are the typical USCG fees for an original lower-level officer endorsement?
Under 46 CFR 10.219, a typical original lower-level officer total is about $240: $100 evaluation, $95 examination, and $45 issuance. Confirm the current National Maritime Center fee schedule before applying.
What environmental rules are tested on the Chief Engineer-OSV exam?
The Q683 module tests MARPOL requirements such as the 15 ppm machinery-space bilge discharge limit and the Oil Record Book, the prohibition on discharging plastics under Annex V, U.S. requirements including the Oil Pollution Act of 1990 (OPA 90), and spill-response and hazardous-material handling relevant to OSV engineering operations.