The Master 100 GT credential authorizes you to serve as master of any vessel up to 100 Gross Tons. It's the next step above the OUPV (6-pack), and the license you need to run an inspected passenger vessel carrying more than 6 paying passengers. Most fishing charter captains, sightseeing boat operators, and small ferry operators hold the Master 100 GT Near Coastal or Inland endorsement.
Near Coastal vs. Inland
The Near Coastal endorsement covers any U.S. navigable waters out to 200 nautical miles offshore, including the Great Lakes. It requires sea service that includes offshore time and STCW Basic Training. The Inland endorsement covers inland rivers, lakes, and bays inside the COLREGS Demarcation Line — STCW is not required on most inland routes. Most candidates who intend to run coastal charter or ferry operations pursue Near Coastal.
Sea service requirement
You need 360 days on qualifying waters, with at least 90 days offshore (beyond 3 nautical miles from shore) for the Near Coastal endorsement. Days must be underway, not at anchor. Time served as master or mate, crew, or even as a documented passenger on a commercial voyage can count — but you'll need signed verification for every day claimed.
Exam modules (5 written tests)
- Rules of the Road — 80% passing threshold. The hardest module at every license level.
- Charts & Navigation — buoyage, aids to navigation, chart symbols, compass correction (70%)
- Navigation Problems — dead reckoning, speed-time-distance, current, tides (70%)
- Deck General — cargo, stability, anchoring, mooring, seamanship (70%)
- Safety — firefighting, damage control, survival craft, GMDSS equipment (70%)
STCW Basic Training
The Near Coastal endorsement requires STCW Basic Training, which consists of Basic Safety Training (BST — firefighting, survival, first aid, personal safety), PSSR (Proficiency in Survival Craft and Rescue Boats), and the Security Awareness module. These are completed at a STCW-approved training provider — typically a 4–5 day in-person course — before your NMC application can be finalized.
Typical exam timeline
Most candidates are exam-ready in 4–8 weeks of focused preparation. Rules of the Road and Navigation Problems are the modules where time is best invested. Navigation Problems requires comfort with basic trigonometry — practice vector diagrams and current calculations until they're automatic. Safety catches candidates who skip it assuming it's easy.