When Master 50 makes sense#
If your boat is between 6 passengers (OUPV ceiling) and 50 GT, Master 50 is the right credential. Many charter sport-fish operators in this size run Master 50 because they don't need the additional 50 GT of authority that Master 100 grants. If you have not yet confirmed whether the operation is passenger-for-hire or a private recreational trip, start with do I need a captain's license before sizing the Master route.
Sea service and tonnage#
For Near-Coastal Master less than 100 GRT, the baseline is 720 days of deck-department service, with up to 360 inland-water days allowed as substitute service. For Great Lakes/Inland, the baseline is 360 total days. The 50 GRT limit comes from the same 46 CFR 11.422 formula: the current NMC Near-Coastal checklist shows 180 days on vessels of 26 GRT or above, or 360 days on vessels of 17 GRT or above; the Great Lakes/Inland checklist shows 90 days on 26+ GRT or 180 days on 17+ GRT. Those day counts only hold up if the service is documented correctly — see how to log qualifying days and vessel tonnage on CG-719S in the USCG sea time requirements guide.
Path from OUPV#
Most candidates earn OUPV first, log enough qualifying service on appropriately sized vessels, then apply to upgrade to Master 50. The Approval to Test letter controls exactly which modules you repeat. The current NMC exam guide lists Q165 Navigation and Deck General-Safety for a raise of grade from OUPV Near Coastal to Master Near Coastal less than 100 GRT; chart plotting is not automatically an additional module because standard OUPV routes already test it.