How to Study for the USCG 100-Ton Master Exam: A Week-by-Week Plan

The jump from a 6-pack to a 100-Ton Master is a real step up, and the studying has to reflect that. You are now master of an inspected vessel carrying more than six passengers, which means the Coast Guard tests you harder on seamanship, weather, and the precise mechanics of Rules of the Road. The deck-general bank is bigger and meaner, the chart work expects more, and on top of the written modules you will sit an oral exam where an examiner asks you questions face to face and watches how you think.

So you cannot study for the 100-Ton the way you studied for the 6-pack. You need a longer runway, a schedule that builds weather and stability competence you may not have, and dedicated oral-exam reps. This is a five-week plan with daily targets. For the syllabus — exactly which modules and how many questions — see the 100-Ton license page. What follows is the how-to-study method.

Start With a Cold Diagnostic, Then Plan Around It

Before week one, take a full diagnostic across every module without studying first. The number you care about is not the average — it is the spread. Most candidates coming up from a 6-pack are solid on basic Rules and weak on the things the 100-Ton adds: meteorology, deeper deck general, and stability concepts.

Run the diagnostic across rules-of-the-road, deck-general, navigation-general, chart-plotting, meteorology, and safety. Write down all six scores. Whichever two are lowest get extra sessions baked into the plan below. There is an old island saying about reading the sky before you leave the harbor — your diagnostic is reading the sky on your own knowledge.

The Five-Week Plan

This assumes roughly 10 to 12 hours of study per week. Compress to four weeks if you have more daily time, but keep the order. The sequence is deliberate: foundations, then mechanics, then weather and safety, then pure drilling, then simulation plus oral prep.

Week 1 — Rules and Deck Foundations

• Day 1: Read all 38 Rules of the Road in one sitting for structure. Note the four blocks: any-visibility conduct (4-10), in-sight conduct (11-18), restricted visibility (19), then lights, shapes, and signals (20-37). Read Rule 5 and Rule 6 carefully — lookout and safe speed underpin every collision question.
• Day 2: Steering and sailing. Drill Rule 13 (overtaking), Rule 14 (head-on), Rule 15 (crossing), and Rule 18 (responsibilities between vessels). 30 questions on these only.
• Day 3: Deck general — anchoring, ground tackle, lines, breaking strains, blocks and tackle. 35 questions.
• Day 4: Deck general — firefighting, fire classes and agents, watchkeeping, helm commands. 35 questions.
• Day 5: Re-do every miss from the week. Missed questions are your real syllabus.
• Weekend: 30-question timed Rules block. Track time per question.

Week 2 — Navigation and Chart Plotting

• Day 1: Compass theory and the TVMDC conversion chain, true and magnetic, variation and deviation, applying a deviation table. 30 navigation-general questions.
• Day 2: Physical plotting practice. Parallel rules or course plotter, dividers, pencil — plot six courses by hand on a training chart. The exam is paper and real tools; build that muscle memory now.
• Day 3: Set and drift, current sailing, course made good, ETA from speed and distance. Six full chart problems.
• Day 4: Tides, currents, the Light List, Coast Pilot, and aids to navigation. 30 navigation-general questions.
• Day 5: Timed chart plotting, four minutes per problem. Speed is graded indirectly through the clock.
• Weekend: 40-question mixed navigation-general and chart-plotting block.

Week 3 — Weather, Safety, and Stability

This is the week the 100-Ton earns its reputation. The 6-pack barely touched these. Now they are graded.

• Day 1: Meteorology — pressure systems, fronts, the relationship between wind and isobars, fog formation, cloud types as weather indicators. 30 meteorology questions.
• Day 2: Meteorology continued — reading a weather map, heavy-weather tactics, tropical systems, and forecasting basics. 30 questions.
• Day 3: Safety — lifesaving equipment requirements, distress signals, abandon-ship and man-overboard procedures, PFD and EPIRB rules. 30 safety questions.
• Day 4: Stability and damage control — center of gravity, free-surface effect, the difference between stiff and tender, downflooding. 25 deck-general and safety questions on stability.
• Day 5: Re-do all misses from Days 1 through 4. Patch the weather and safety leaks now while there is still time.
• Weekend: Full timed practice exam, scored by module. Note your two lowest.

Week 4 — Drill the Bank Hard

The NMC bank is public and finite. This week is high-rep repetition with a miss log.

• Day 1: Full lights and shapes sweep. Arc widths cold: masthead 225, sidelights 112.5 each, sternlight 135, all-round 360. Drill vessel lights identification to reflex speed.
• Day 2: Full sound-and-fog-signal sweep, including the Inland-versus-COLREGS divergences that the NMC loves to flip on you.
• Day 3: Full deck-general bank sweep. Anything under 80% gets re-drilled.
• Day 4: Full navigation-general bank sweep.
• Day 5: Patch your two lowest modules from last weekend's exam — nothing else.
• Weekend: Two full timed exams on separate days. No notes, no pausing.

Week 5 — Simulate, Patch, and Prep the Oral

• Day 1: Full-length timed exam across all modules. Score by module; you want 82% or better everywhere.
• Day 2: Patch day on your weakest two modules only.
• Day 3: Oral-exam prep (see below). Spend the whole session on it.
• Day 4: Final full simulation on the practice exam, plus a second oral run-through.
• Day 5: Light review only — your notes, arc widths, TVMDC, one chart problem. No new material.

How to Use Practice Tests Properly

A practice test is a measuring tool, not a trophy. Three habits make it work:

Score by module, every time. Each 100-Ton module is its own gate at 70%. A strong overall number can mask a failing module. Your tool should split the score the way the exam does.

Keep a running miss log. One line per missed question on why you missed it. After five weeks that log is the most targeted study guide you own.

Drill timed at least weekly per module. Test-day pressure is real and it is the variable a calm living-room session cannot replicate. Practice the pressure on purpose.

Weak-Area Drilling

When a module sags, isolate the leak instead of re-reading the whole subject. If crossing situations are the problem, run nothing but crossing, overtaking, and head-on drills for a session. If weather is the gap, hammer meteorology until pressure-and-wind questions are automatic. Rule of thumb: any sub-topic under 80% on a category drill earns its own dedicated session before exam day.

Preparing for the Oral Exam

The 6-pack has no oral. The 100-Ton does, and people who only studied for a written test get caught flat. The oral examiner is not trying to trick you — they want to hear you reason out loud like a master who is responsible for an inspected vessel and her passengers.

Practice talking, not just bubbling. Say your answers aloud, in full sentences. "Given a vessel on my starboard side in a crossing situation, I am the give-way vessel under Rule 15, so I will take early and substantial action to starboard and avoid passing ahead of her." If you can only point at the right multiple-choice letter, you are not ready for the oral.

Expect scenario questions. Restricted visibility maneuvers, fire in the engine room, man overboard, anchoring in a crowded harbor, a passenger medical emergency. Have a calm, ordered procedure for each — first action, second action, who you call, how you communicate.

Know your light and signal answers verbally. A classic oral move: "You see two all-round red lights in a vertical line — what is it and what do you do?" You should answer without hesitating that it is a vessel not under command, and explain your responsibility toward her under Rule 18.

Run mock orals. Have someone fire questions at you, or talk through scenarios out loud solo. Use the oral exam guide to see the format and the kinds of questions examiners actually ask, then rehearse until your answers come out steady.

Knowing You Are Ready

You are ready when you consistently score 82 to 85% or better on full-length practice exams across every module — your normal repeated score, not a one-time best — and when you can talk through standard scenarios out loud without freezing. The buffer above the 70% line absorbs test-day nerves, and the verbal fluency is what carries you through the oral.

If any module is still under 75% in the final two weeks, or you cannot yet explain your collision-avoidance reasoning aloud, move the date. Walking in genuinely ready beats a re-sit and a re-scheduled oral every time.

Binnacle AI is not affiliated with the U.S. Coast Guard or the NMC. Exam structures and question counts reflect current NMC guidance as of 2026 — confirm at the NMC website before sitting your exam. This article is informational, not legal or licensing advice.