Deck

USCG Master of Vessels Less Than 100 GRT

USCG-MASTER100

Modules
5
Lessons
15
Questions
75

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.

Aligned to the published USCG framework. Official source. Drafted from 46 CFR Parts 10 & 11 (esp. 11.422, 11.428, 11.455, 11.457), 33 CFR Parts 62/80/83, and NMC checklist MCP-FM-NMC5-15 (08), 15 Sep 2025..

Rule notes (9)
  1. Rule to know

    Yacht days count one for one, not time-and-a-half

    A creditable day is 8 hours of watchstanding or day-work (46 CFR 10.107); a 14-hour charter day is still one day. The 1.5-day credit in 10.232 is for vessels authorised to run two watches under 46 U.S.C. 8104 and 15.705. Yachts are exempt from the three-watch rule, which is not the same as being authorised for two. Count one day per day unless the NMC says otherwise in writing.

    Sources

  2. Rule to know

    Foreign-flag time only counts for a raise once you hold the endorsement

    46 CFR 10.232(f)(2): for a raise of grade, foreign-vessel service counts only if earned while holding a valid US endorsement. Service on foreign-flag yachts can count towards an original endorsement if the NMC finds it a fair equivalent, and letters must be in English or officially translated. Get your first MMC early so later yacht seasons count.

  3. Sources disagree

    Recency: 3 months in 3 years (CFR) or 90 days in 7 (checklist)?

    46 CFR 11.201(c)(1)(i) requires 3 months' service within the past 3 years. NMC checklist MCP-FM-NMC5-06 (15 Sept 2025) says 90 days in the past 7 years on vessels of 50 GRT (Master <500) or 100 GRT (Master <1,600). Plan to meet the 3-year figure until the NMC confirms which it applies.

  4. Rule to know

    Foreign inland waters are not oceans

    For sea service credit, 46 CFR 10.107 says "the inland waters of another country are not considered oceans." Canal, river and harbour-refit time abroad will not build Able Seafarer-Unlimited or ocean officer service. Letters should name the waters so the evaluator can credit them correctly.

  5. Rule to know

    GT-only yachts: tonnage is credited as GRT for officer endorsements

    Many large yachts carry only a Convention GT figure. For national officer endorsements, 46 CFR 11.211(h) credits a vessel measured only under the Convention system as GRT. Whether the NMC applies the same rule to AB-Limited's 100 GRT threshold is not confirmed. Make sure every letter states the tonnage from the registry document, not the brochure.

  6. Not confirmed

    Does STCW apply to a private US-flag yacht?

    The STCW Convention excludes pleasure yachts not engaged in trade, but 46 CFR Part 15 does not repeat that exclusion in terms. How the Coast Guard treats a US-flag yacht used privately, including on foreign cruising, was not settled by the sources read. If the yacht is purely private, get the Coast Guard's position in writing.

  7. Rule to know

    MCA certificates are not US endorsements

    US STCW endorsements need Coast Guard-approved or accepted training (46 CFR Parts 10–12). An MCA-approved STCW refresher proves your MCA certificate, not your MMC endorsement; use a Coast Guard-approved course unless the NMC confirms otherwise. Policy Letter 07-01 on foreign-approved courses is listed by the NMC as active, but its text was not available to check.

    Sources

  8. Recent change

    Seaman became Seafarer: new endorsement titles from 17 January 2025

    The Coast Guard rule effective 17 January 2025 renamed Ordinary Seaman to Ordinary Seafarer, Able Seaman to Able Seafarer and Lifeboatman to Lifeboat Operator. You do not need to apply to change titles; they update at your next transaction. The statute (46 U.S.C. 7306) and many old letters and job adverts still use the old names.

    Sources

  9. Not confirmed

    In-port and shipyard days on yachts

    No NMC source found addresses in-port, at-anchor or yard days on yachts specifically, and NMC letters are asked to show underway days. Count yard periods conservatively and keep your own log of underway days, waters, tonnage and watches.

    Sources

USCG-MASTER100-M1 · The credential

4 lessons

USCG-MASTER100-M2 · Raising and extending the ticket

3 lessons

USCG-MASTER100-M3 · Deck General (exam module Q160)

3 lessons

USCG-MASTER100-M4 · Deck Safety (exam module Q161)

3 lessons

USCG-MASTER100-M5 · Navigation (exam modules Q162 and Q163)

2 lessons