Where the demarcation lines fall (33 CFR Part 80)
33 CFR Part 80 — the COLREGS Demarcation Lines — fixes the exact boundary between the two rule sets. The lines run across harbour entrances, the mouths of bays and sounds, and the seaward ends of jetties, so the water just inside a sea buoy can be Inland while the water a few hundred yards farther out is governed by the International Rules.
Inside the lines you are on Inland waters: bays, sounds, the Great Lakes, the Intracoastal Waterway, and inland rivers. Outside them you are on COLREGs / near-coastal waters. An OUPV Inland endorsement keeps you inside those lines; OUPV Near-Coastal is what lets you legally cross them with paying passengers aboard.
The sea-time difference: 90 ocean days
Both endorsements are built on the same 360-day OUPV sea-service base, but Near-Coastal adds a route condition on top of it. Under 46 CFR 11.467, an OUPV applicant needs 360 days of qualifying service; the Near-Coastal route additionally requires that at least 90 of those days be served on ocean or near-coastal waters. OUPV Inland has no ocean-day requirement — all 360 days may be inland, bay, or Great Lakes service.
This is the practical fork for most applicants. If your logbook is entirely lake, river, sound, or bay time, you can qualify for OUPV Inland now and would need to accumulate the 90 ocean / near-coastal days before stepping up to Near-Coastal. (A day of service is 8 hours; see our sea-time guide for how the Coast Guard counts and documents days underway.)
The exam: Inland Rules vs International COLREGs
The Rules-of-the-Road module of the OUPV written exam is keyed to your route. Inland candidates are tested on the Inland Navigation Rules (33 CFR Part 83). Near-Coastal candidates must additionally know the International Rules — the COLREGs — that govern waters outside the demarcation lines.
The two rule sets are written almost word-for-word the same, so the extra study load is not a second body of law. It is concentrated in the handful of rules that actually diverge, plus the higher passing standard the Rules module carries across every deck exam (90% on the Rules of the Road versus 70% on the other modules).
Where the two rule sets diverge
The differences that matter on the Near-Coastal exam are concentrated in five rules. Rule 9 (narrow channels) carries extra Inland provisions for bends and obstructed channels. Rule 10 governs offshore Traffic Separation Schemes under COLREGs but Vessel Traffic Services inland. Rule 24 sets different towing lights and shapes. Rule 28 (vessels constrained by their draft) is a COLREGs-only signal with no Inland equivalent, because inland waters are not deep-draft ocean lanes. Rule 34 sound signals are the classic trap: under the Inland Rule 34 intent-signal version, manoeuvring whistle signals are signals of intent (you sound, the other vessel agrees, then you act), while under COLREGs they are signals of action (you sound as you actually alter course).
Our Inland-vs-International Rules comparison lays these five out side by side; a Near-Coastal candidate should be able to state each divergence cold before sitting the Rules of the Road.
How far offshore each lets you run
OUPV Inland authority stops at the demarcation lines. OUPV Near-Coastal extends authority to waters not more than 100 nautical miles offshore — the Coast Guard National Maritime Center notes that OUPV Near Coastal endorsements may be limited to 100 miles offshore based on the service you document. Neither OUPV endorsement is valid for international voyages, and neither lets you carry more than six passengers for hire.
If your business plan is canyon fishing, bluewater reef trips, island runs that leave protected water, or any route that crosses the demarcation line, you need Near-Coastal. If you run a lake, bay, sound, or river operation that never leaves Inland waters, Inland is the correct — and faster — credential.
Upgrading Inland to Near-Coastal later
You do not have to choose perfectly the first time. An OUPV Inland holder can add the Near-Coastal route once the 90 ocean / near-coastal days are logged and documented, without re-taking the entire credential — the upgrade is processed against the same OUPV, with the Near-Coastal Rules-of-the-Road material added to the exam scope as required.
The usual path for a new charter operator who fishes mostly inside but occasionally runs offshore is to earn Inland first (faster to qualify), build the ocean days during the season, and upgrade to Near-Coastal at renewal or when the offshore work justifies it.