CFR Demystified

By Captain Mike · 50 years at sea · former MITAGS faculty
Part numbers checked against eCFR · September 2026

Stop flipping pages. Learn the neighborhoods.

Nobody memorizes the Code of Federal Regulations, and you don't need to. What separates a mariner who finds the answer in two minutes from one who burns twenty is knowing which neighborhood the answer lives in before opening the book. For most maritime questions, that means two titles.

33 CFRNavigation and Navigable Waters. How you operate on the water: navigation safety, ports, pollution prevention, security.

46 CFRShipping. The vessel and the people: credentials, manning, inspection, construction, lifesaving and firefighting equipment.

49 CFRTransportation. The one people forget: hazardous materials, including packaged hazmat carried by vessel.

A rough rule of thumb: 33 CFR tells you how to operate. 46 CFR tells you what the ship and crew must be.

Where to start looking

If the question is about...	Start here	Why
Navigation safety: equipment, voyage planning, testing gear before getting underway	33 CFR 164	The Navigation Safety Regulations.
Rules of the Road, inland waters	33 CFR 83	The Inland Rules are codified in the CFR. The International Rules (COLREGS) are published with them in the Navigation Rules handbook.
Vessel traffic services, ports and waterways safety	33 CFR 161 and nearby parts	Parts 160 to 167 cover ports and waterways safety.
Oil and garbage pollution, MARPOL	33 CFR 151	Vessel pollution prevention, including garbage and oil record keeping.
Oil and hazmat transfers	33 CFR 155 and 33 CFR 156	Equipment, procedures and the person in charge of transfers.
Vessel security	33 CFR 104	Vessel security plans and officers.
Licenses, ratings, endorsements, sea time	46 CFR Subch. B	Parts 10 to 16: everything about merchant mariner credentials.
Manning: how many crew, what credentials	46 CFR 15	Manning requirements.
Lifesaving appliances and drills	46 CFR 199, plus the vessel's own subchapter	Many vessel types also carry lifesaving and drill rules in their own subchapter.
Small passenger vessels (under 100 GT)	46 CFR Subch. T	Construction, equipment and operations for "T-boats."
Tank vessels	46 CFR Subch. D	Parts 30 to 39. But see the tankerman example below.
Packaged hazardous materials	49 CFR Part 176	Hazmat carriage by vessel.

The exception that teaches the rule: tankerman

Real questions don't always stay in one neighborhood, and tank vessels prove it. A single cargo transfer can touch three titles at once:

33 CFR

The transfer itself

Transfer procedures, equipment, the declaration of inspection, and the person in charge 33 CFR 155 33 CFR 156

46 CFR

The vessel and the tankerman

Tank vessel construction and operations 46 CFR Subch. D, and tankerman endorsements in Part 13 46 CFR 13

46 CFR / 49 CFR

The cargo

Bulk dangerous cargoes in Subchapter O, and hazmat classification in 49 CFR

That's why "33 or 46?" is the wrong first question. The right one is "What am I actually being asked about: the operation, the vessel, the person, or the cargo?" Answer that and the neighborhood usually picks itself.

How to search the CFR like a pro

Use the subchapter, not the whole title

46 CFR is organized by vessel type into subchapters (D for tank vessels, T for small passenger vessels, and so on). Once you know the vessel type, you've cut the haystack by 90 percent.

Read the definitions section first

Most parts open with definitions, and exam questions love to turn on them. "Person in charge," "passenger," and "underway" all have specific regulatory meanings.

Check "applicability" before trusting an answer

Near the start of most parts is a section saying which vessels it covers. A rule that's correct for a tank ship may not apply to a barge, or to a vessel under a certain tonnage.

Use the official eCFR online

The free eCFR at ecfr.gov is updated daily and searchable. Old printed copies and PDFs floating around the internet are often out of date.

For credentials, the CFR is only half the story. The Coast Guard’s NVICs explain how it applies the regulations. See NVICs & Approved Courses →