- National Barge Supervisor is examined through USCG National Maritime Center code MODU02, split into three modules.
- The modules are Q100 (Rules of the Road), Q437 (Deck General Safety), and Q438 (MODU Operations).
- Q100 requires 90%; Q437 and Q438 each require 70%. These are module pass marks, not content weights.
- Each module lists 50 questions, so the original endorsement module set totals 150 by simple addition.
What This Cheat Sheet Covers
This page is a compact reference for candidates working toward the National Barge Supervisor endorsement, examined by the United States Coast Guard National Maritime Center (NMC). It is built to be skimmed the night before you sit a module, not read cover to cover. If you want the long-form walkthrough instead, start with the NBS study guide and come back here for the condensed version.
Everything below is tied to the NMC's published examination index for code MODU02 and the NMC Deck and Engineering Guide section covering Mobile Offshore Drilling Unit endorsements. Where the official sources are silent (topic percentage weights, a whole-set duration, current pass rates, fees), this sheet stays silent too rather than guessing. For a practice environment that mirrors the module structure, the NBS practice test site is the natural companion to this reference.
The Facts at a Glance
Here is the whole credential on one table. Every number comes from the NMC examination index and the Deck and Engineering Guide (regulations effective March 24, 2014, section 2.1.6, Mobile Offshore Drilling Unit Endorsements, printed page 35).
| Item | What the Official Sources Show |
|---|---|
| Governing body | United States Coast Guard National Maritime Center |
| Examination code | MODU02 |
| Number of modules | 3 (Q100, Q437, Q438) |
| Questions per module | 50 |
| Total across the module set | 150 (arithmetic sum, 3 × 50) |
| Q100 pass mark | 90% |
| Q437 pass mark | 70% |
| Q438 pass mark | 70% |
| Topic percentage weights | Not asserted; the three lines are modules, not weighted domains |
| Whole-set duration | Not asserted; a module set is not a single timed sitting |
| Current pass rate | Not asserted |
| Current fee | Not asserted |
This review was prepared as of October 10, 2026. That date is a review date only, and it should not be read as a claim that the NMC guide was revised in 2026. The guide referenced is the one based on the March 24, 2014 regulations.
Domain 1: Rules of the Road (Q100)
Q100 is titled Rules of the Road: International and Inland. It carries the highest pass mark in the set at 90%, which makes it the module where a handful of misses matters most. With 50 questions listed, a 90% threshold means the margin for error is small.
Q100: Rules of the Road, International and Inland
This is the navigation-rules foundation. Candidates must be able to apply the rules, not merely recite them, and must keep the international and inland regimes distinct in their heads.
- Know where the international rules and the inland rules differ, since questions can hinge on the distinction
- Lights, shapes, and sound signals for vessels in various situations, including vessels restricted in their ability to maneuver
- Responsibilities between vessels: stand-on and give-way, overtaking, crossing, and head-on situations
- Conduct in restricted visibility and safe speed considerations
- Narrow channel and traffic-related rules relevant to working near fixed and floating structures
Because this is a high-threshold module, drill it until your accuracy is consistent rather than lucky. Candidates who treat Q100 as "the easy navigation one" and shortchange it tend to be surprised by how unforgiving a 90% mark is. The NBS passing score guide explains how module thresholds work in practice.
Domain 2: Deck General Safety (Q437)
Q437 is titled Barge Supervisor Deck General Safety. The pass mark is 70%, and it is the module where practical deck judgment meets regulation-flavored questions.
Q437: Barge Supervisor Deck General Safety
Think of this as the working-deck safety module. Questions reward candidates who have actually thought through how a deck operation goes wrong and what a supervisor does about it.
- Safe work practices on deck, including hazard recognition before a task begins
- Personal protective equipment and the supervisor's role in ensuring it is used
- Line handling, mooring, and tension hazards, including snap-back zones
- Handling and securing of cargo and equipment on deck
- Communication during deck evolutions and the role of clear signals
- Emergency response awareness at the deck level, such as man-overboard and fire basics
A supervisor-level safety exam differs from an able-seaman style one in emphasis: you are expected to think about planning, briefing, and accountability for other people's safety, not only your own. If you are weighing whether the supervisory step is a good fit, How Hard Is the NBS Exam? frames the difficulty honestly.
Domain 3: MODU Operations (Q438)
Q438 is titled Barge Supervisor MODU Operations, again at a 70% pass mark. This is the module that ties the endorsement to its reason for existing: mobile offshore drilling units and the barge-type and unit-handling work around them.
Q438: Barge Supervisor MODU Operations
This module covers how a mobile offshore drilling unit is operated and kept safe as a floating platform, with the barge supervisor's responsibilities front and center.
- Stability and ballast concepts as they apply to a floating unit, including how weight changes affect trim and heel
- Watertight integrity and the importance of keeping closures and openings properly managed
- Positioning and mooring or station-keeping considerations for a unit on location
- Emergency organization, muster, and the supervisor's role during casualties
- Coordination between marine crew and drilling-side personnel
- Weather and sea-state awareness and its effect on operating decisions
Key Takeaway
Q100 is the strictest threshold, but Q438 is the most specialized content. Plan to spend the most unfamiliar-material time on MODU operations and the most precision-drilling time on Rules of the Road.
Module Math: Questions and Pass Marks
The easiest way to misread this credential is to treat the three lines as a weighted blueprint. They are not. The NMC index lists examination modules, each with its own question count and pass mark. Here is what that implies for your preparation.
- Each module stands alone. A strong Q437 result does not offset a weak Q100 result. Each module is judged against its own threshold.
- Fifty questions per module. At 90% on Q100, that means the threshold is demanding relative to the 70% modules. At 70% on Q437 and Q438, you have more room, but still must be broadly solid across every topic in the module.
- 150 is a sum, not a sitting. The 150-question total is simply 3 × 50 across the original endorsement module set. It does not describe one continuous exam, and no single whole-set duration is asserted.
- No topic percentages. Do not budget study hours by an invented weighting. Budget them by module and by your own weak spots.
For a fuller treatment of how thresholds translate into preparation targets, see NBS Passing Score: Exactly What You Need to Pass.
Sequencing Your Review by Module
This is the one place generic study structure earns a spot, and it is tied directly to the three modules. The logic: start with the module whose threshold punishes sloppiness, then build into the module that demands the most new knowledge, and finish with consolidation.
Q100 Foundation
- Re-learn lights, shapes, and sound signals; keep international and inland differences side by side
- Work situation-based practice questions until you are well clear of the 90% line
Q437 Deck Safety
- Walk through typical deck evolutions and name the hazards and the supervisor's controls for each
- Review PPE, line handling, and emergency response basics
Q438 MODU Operations
- Spend the most time here if you have limited offshore drilling-unit exposure
- Focus on stability, watertight integrity, positioning, and emergency organization
Weak-Spot Pass and Q100 Refresh
- Return to whichever module you missed the most on in practice
- Do a final Q100 pass, since its threshold leaves the least slack
You can run these drills against realistic questions on the NBS Exam Prep practice test, and the full study guide expands each week into specific tasks. Before committing to a schedule, confirm you actually qualify by reading NBS Requirements: Eligibility, Prerequisites & How to Qualify.
Where the Endorsement Gets Used
The National Barge Supervisor endorsement belongs to the offshore and marine-operations world, specifically work connected to mobile offshore drilling units. In practical terms, the employers who care about it are operators and contractors that run or support floating drilling units, along with marine service companies that supply crews for that environment.
Because this sheet does not assert salary figures, hiring volumes, or demand statistics, it will not put numbers on any of that. If you are weighing the career side, the qualitative discussion in NBS Jobs, the NBS Salary Guide, and Is the NBS Certification Worth It? is the better place to continue. The general question of what the credential represents is covered in What Is NBS Certification?.
What This Sheet Will Not Claim
A good cheat sheet is as clear about its limits as its facts. Here is what the official sources provided for this review do not establish, and what you should verify directly with the National Maritime Center before relying on it.
- Fees. No current fee is asserted. Confirm costs directly, and see NBS Certification Cost for how to think about the cost picture.
- Pass rates. No current pass rate is asserted. The NBS pass rate article discusses what can and cannot be said from available data.
- Test dates. Scheduling and any testing windows should be confirmed with the NMC; see NBS Exam Dates for the general approach.
- Weights and timing. No topic percentage weights and no single whole-set exam duration are asserted, because the module set is not a single timed sitting.
- Guide currency. The guide referenced is based on regulations effective March 24, 2014. The October 10, 2026 date is when this review was prepared, not when the guide changed.
Key Takeaway
Before exam day, check the NMC's MODU02 page and the Deck and Engineering Guide yourself. This sheet is a study aid built from those sources, and the NMC remains the authority on current procedure.
FAQ
NBS means National Barge Supervisor, a Coast Guard endorsement examined under NMC code MODU02. For background on the acronym, see What Does NBS Stand For?.
Three: Q100 (Rules of the Road: International and Inland), Q437 (Barge Supervisor Deck General Safety), and Q438 (Barge Supervisor MODU Operations). Each lists 50 questions, for 150 across the set by simple addition.
Q100 requires 90%, while Q437 and Q438 each require 70%. These are module pass marks and do not represent content weightings.
No. The total is the arithmetic sum of three 50-question modules. A module set is not a single timed sitting, and no whole-set duration is asserted by the sources used for this page.
Most candidates benefit from starting with Q100 because its 90% threshold leaves little slack, then moving to Q437 and Q438, and finishing with a Q100 refresh. Adjust based on your own background, particularly if you have little exposure to mobile offshore drilling unit operations.