USCG-MASTER100-L1.1

What Master under 100 GRT authorises

The OUPV lets you carry six people for money on a boat nobody inspects. The Master under 100 GRT lets you command an **inspected** vessel carrying a great many more. That is the whole difference, and it is a large one.

Entry & progression

Credential: Master of self-propelled and/or auxiliary sail vessels of less than 100 GRT. Entry: age 19, and 2 years' deck service for the near-coastal route. Builds on: the OUPV, though it is not a prerequisite.

What changes

OUPV Master < 100 GRT
Passengers Six or fewer As many as the vessel's Certificate of Inspection permits
Vessel Uninspected only Inspected or uninspected
Tonnage Under 100 GRT, no tiers Under 100 GRT, tiered at 25 / 50 / 100 by formula
Minimum age 18 19
Route ceiling Near coastal, 100 miles Near coastal, 200 miles
Sea service (near coastal) 12 months 2 years in the deck department

Note the two lines that surprise people. The tonnage is tiered — you do not simply get 100 GRT, you get whatever the formula gives you, and it may be 25. And the near-coastal limit is 200 miles, not the 100 that constrains an OUPV. A Master 100 and an OUPV standing on the same beach hold licences valid on different water.

The ceiling: near coastal, and no further

WARNING — Master 100 GRT is never issued for oceans The NMC checklist states it flatly: "Master 100 GRT will not be issued for oceans, only NC." There is no ocean route at this tonnage, and no amount of blue-water service will produce one. Above near coastal, the ladder continues at Master 200 GRT (46 CFR 11.426) and beyond — but not here.

Inspected vessels: what you are taking on

Command of an inspected vessel means the vessel carries a Certificate of Inspection, and the COI is a document you must be able to read and obey. It states the route she may run, the maximum number of persons she may carry, the crew she must carry, and the equipment she must have aboard.

The COI is not advisory. Exceeding the persons figure, sailing outside the stated route, or sailing without the manning it requires puts you outside the vessel's certification — and the master is the person the Coast Guard holds responsible. Read it on the day you join, and read it again whenever it is reissued.

Uninspected vessels too

The credential covers both. A Master under 100 GRT may command an uninspected passenger vessel exactly as an OUPV holder can — the higher ticket subsumes the lower one. What it does not do is remove the six-passenger limit on an uninspected vessel: that limit belongs to the vessel's status, not to your licence.

This confuses people every year. Holding a Master 100 does not let you put twenty passengers on an uninspected boat. It lets you command a boat that has been inspected and certificated to carry twenty. The credential and the vessel have to match.

The word 'Master'

This is a command licence. It carries the authority to make the final decision aboard and the responsibility that comes with it — for the vessel, for the crew, and for every person you carry. The regulations that follow in this course are the floor. Nothing in them relieves you of the ordinary practice of seamen, and no certificate ever has.

The exam is correspondingly harder than the OUPV's: five modules instead of four, with Deck General and Deck Safety examined separately. It is a different standard, and it is meant to be.

Practice questions

5 questions
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The principal difference between an OUPV and a Master under 100 GRT is that the Master: (a) May carry six passengers instead of five (b) May command inspected vessels, carrying as many passengers as the Certificate of Inspection permits (c) May operate on oceans (d) Requires no sea service

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For a Master under 100 GRT, near-coastal waters extend to: (a) 100 miles offshore (b) 200 miles offshore (c) 50 miles offshore (d) The territorial sea

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A Master under 100 GRT endorsement may be issued for: (a) Oceans, with sufficient service (b) Near coastal at most — it is never issued for oceans (c) Any route worldwide (d) Oceans only on sail vessels

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The minimum age for a Master of vessels of 25 to 200 GRT is: (a) 16 (b) 18 (c) 19 (d) 21

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recall · core

A vessel's Certificate of Inspection states: (a) Only the vessel's tonnage (b) The route, the maximum persons carried, the required crew and the required equipment (c) The master's qualifications (d) The vessel's insurance value

AI-drafted catalogue content pending SME review. USCG requirements change; verify every figure against the National Maritime Center and the current CFR before relying on it for an application.

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