Vessel Inspection & Certification
COI requirements, Subchapter T and K applicability, load lines, stability letters, drydock intervals, Port State Control, and USCG documentation endorsements — every inspection topic tested on the USCG exam.
1. Inspected vs. Uninspected Vessels
The most fundamental distinction in vessel regulation: does your vessel require USCG inspection and a Certificate of Inspection, or does it operate as an uninspected vessel?
Inspected Vessels
- ▶Carry passengers for hire (commercially)
- ▶Subject to periodic USCG inspection
- ▶Must hold a valid Certificate of Inspection (COI)
- ▶Must post COI in conspicuous location
- ▶Governed by applicable subchapter (T, K, H, M)
- ▶Manning requirements specified on COI
- ▶Examples: charter boats, passenger ferries, dive boats, water taxis
Uninspected Vessels
- ▶Not required to carry a COI
- ▶Recreational vessels (not for hire)
- ▶Uninspected passenger vessels (UPV) — carry 7 to 12 passengers for hire
- ▶Still subject to federal safety equipment rules (46 CFR Subchapter C)
- ▶OUPV (6-pack) license covers UPV operations
- ▶Must have stability letter if carrying 7–12 passengers
- ▶Examples: private yachts, OUPV-operated fishing charters with 6 or fewer passengers
Key Trigger: What Makes a Vessel Inspected?
The primary trigger is carrying passengers for hire in excess of the uninspected passenger vessel limit. If a vessel carries more than 6 passengers for hire (on ocean or coastwise routes) or is over the applicable tonnage threshold, it becomes an inspected vessel requiring a COI.
Exam Point: Subchapter C — Uninspected Vessel Safety Requirements
Even uninspected vessels must comply with 46 CFR Subchapter C — equipment requirements covering life preservers, fire extinguishers, distress signals, and VHF radio. "Uninspected" means no COI and no USCG construction inspection — it does NOT mean no safety requirements. The exam frequently tests this distinction.
2. Certificate of Inspection (COI)
The COI is the operating license for an inspected vessel. Everything the vessel is authorized to do — and every limitation on that authorization — is spelled out in the COI.
| COI Field | What It Specifies |
|---|---|
| Route | Geographic operating area — ocean, coastwise, Great Lakes, rivers, protected waters, or specific named routes |
| Passengers | Maximum number of passengers authorized — cannot be exceeded; also specifies passenger-carrying areas |
| Manning | Minimum crew, required license grades, and watchstanding requirements |
| Equipment | Required lifesaving, fire suppression, navigation, and communication equipment with quantities |
| Freeboard | Minimum freeboard in inches or centimeters — vessel must maintain this distance from waterline to deck |
| Inspection dates | Annual inspection due date; drydock/haul-out due date; next COI expiration |
Posting Requirement
The COI must be posted in a conspicuous place accessible to passengers. On most vessels this means near the helm station, at the gangway, or in the main passenger area. Failure to post the COI is a violation and may be cited during inspection.
COI Violations & Consequences
- Exceeding passenger limit: Grounds for suspension or revocation of master's license
- Exceeding route authorization: Operating outside authorized waters is a serious violation
- Expired COI: Vessel may not carry passengers; master is personally liable
- Missing equipment: USCG may detain vessel until deficiency is corrected
Critical Exam Rule: Route Authorization
A vessel with a COI authorizing "protected waters" or "inland waters" operation cannot legally carry passengers on ocean or coastwise routes even if the vessel is seaworthy. The COI route limitation is absolute. A master who takes passengers outside the authorized route risks license action regardless of whether an incident occurs. This is tested directly on the OUPV and Master exam.
3. Subchapter T, K, H, and M — Applicability
The applicable subchapter determines construction standards, equipment requirements, and inspection procedures. Knowing which subchapter applies to a given vessel type is directly tested on the exam.
| Subchapter | Regulation | Gross Tonnage | Passengers | Voyages | Examples |
|---|---|---|---|---|---|
| Subchapter T | 46 CFR Parts 175–185 | Under 100 GT | Up to 150 | Domestic | Charter fishing boats, small tour boats, water taxis, small ferries |
| Subchapter K | 46 CFR Parts 114–122 | Under 100 GT | More than 150 | Domestic | Large dinner cruise vessels, high-capacity harbor tours, commuter ferries |
| Subchapter H | 46 CFR Parts 70–89 | 100 GT or more | Any number for hire | Domestic and international | Large passenger ferries, ocean-going passenger ships |
| Subchapter M | 46 CFR Parts 136–144 | Any size | N/A (towing service) | Domestic | Tugboats, towboats, articulated tug-barges |
Subchapter T — Key Facts
- Full name: Small Passenger Vessels (Under 100 Gross Tons)
- Passenger limit: Up to 150 passengers (6 or fewer = uninspected)
- GT threshold: Under 100 gross tons
- Construction standards: Hull, machinery, fire protection, stability
- License required: OUPV (up to 6 pax for hire) or Master license for inspected vessel
- Route categories: Ocean, coastwise, Great Lakes, inland, rivers, lakes/bays/sounds, limited coastwise
Subchapter K — Key Facts
- Full name: Small Passenger Vessels Carrying More Than 150 Passengers
- Passenger limit: More than 150 passengers
- GT threshold: Under 100 gross tons
- Enhanced requirements: More rigorous fire suppression, structural standards, crew requirements
- License required: Master license of appropriate tonnage
- Common vessels: High-capacity dinner cruise boats, harbor tour vessels, commuter ferries
Important: The 100 GT and 150-Passenger Thresholds
The 100 GT threshold and the 150-passenger threshold operate independently. A vessel under 100 GT carrying exactly 150 passengers falls under Subchapter T. A vessel under 100 GT carrying 151 passengers falls under Subchapter K. A vessel at 100 GT or more carrying any passengers for hire falls under Subchapter H (or higher regulations), regardless of passenger count. Gross tonnage is a measure of vessel volume, not weight.
4. Load Line Requirements
Load lines ensure vessels are not overloaded to the point of compromising seaworthiness. The Plimsoll mark on the hull shows the maximum permitted waterlines for different ocean zones and seasons.
When Load Lines Apply
- International voyages: Most U.S. vessels over 79 feet on international voyages require a load line certificate
- Domestic voyages: Certain vessels on coastwise or ocean routes depending on service type
- Exemptions: Small passenger vessels under Subchapter T are generally exempt from load line requirements
- Special vessels: Barges, tank vessels, and bulk carriers have specific load line rules
Load Line Certificate
- Issued by USCG or a classification society acting on behalf of the USCG
- Specifies the freeboard — distance from waterline to the main deck edge
- Must be kept aboard the vessel at all times
- Valid for 5 years with annual endorsements
- Vessel must not be loaded beyond the applicable load line mark for the zone and season
Plimsoll Mark Load Line Zones
| Mark | Location on Hull | When Applicable |
|---|---|---|
| S — Summer | White/Black line | Temperate waters, summer season |
| W — Winter | Below S mark | Temperate waters, winter; vessel must ride higher (less load) |
| WNA — Winter North Atlantic | Below W mark | North Atlantic, winter; most restrictive; must carry least cargo |
| T — Tropical | Above S mark | Tropical waters; less restrictive; vessel may be loaded deeper |
| F — Fresh Water | Above T mark | Fresh water load line; vessel floats higher in salt water |
| TF — Tropical Fresh | Highest mark | Fresh water in tropical regions; maximum permitted depth |
Reading the Plimsoll Mark
The Plimsoll mark consists of a circle with a horizontal line through it (the Summer load line center), surrounded by letter-marked horizontal lines above and below. The circle is on the vessel's side, amidships. When the vessel is loaded to the Summer load line, the center of the circle is at the waterline.
5. Annual, Biennial, and Drydock Inspections
Inspected vessels must meet a recurring schedule of USCG inspections. Missing a required inspection can result in the COI expiring and the vessel being prohibited from carrying passengers.
| Inspection Type | Frequency | What Is Inspected | Notes |
|---|---|---|---|
| Annual Inspection | Every 12 months | Full vessel: equipment, structure, machinery, certificates, crew credentials, fire systems, lifesaving appliances | COI renewed upon satisfactory completion |
| Biennial Hull Inspection | Every 24 months | Out-of-water examination of hull bottom, keel, rudder, propeller, shaft, sea cocks, and through-hull fittings | May be combined with annual inspection |
| Drydock / Haul-Out | Every 5 years (steel/fiberglass); every 2 years (wood) | Comprehensive structural inspection, thickness gauging, hull coating, internal frames and structure | Dive survey by approved team may substitute in some cases |
| Continuous Survey | Rolling cycle | Different systems inspected on a rotating basis to avoid single large inspection events | Approved by USCG for certain vessel types |
Wooden Hull Exception — 2-Year Drydock
Wooden-hulled vessels require drydock inspection every 2 years rather than every 5. This is because wood is more susceptible to hidden rot, marine growth penetration, and fastener corrosion. The exam frequently tests this distinction. When you see a question about drydock frequency, always ask: what is the hull material?
6. Stability Letter
A stability letter (or stability booklet) establishes the approved loading conditions under which a vessel may safely operate. It is issued after stability testing and forms part of the vessel's operating documentation.
When a Stability Letter Is Required
- UPV (7–12 passengers): Required for all uninspected passenger vessels carrying 7 to 12 passengers
- Inspected vessels: Required when USCG determines stability analysis is warranted based on vessel design
- Modified vessels: Required after significant structural modifications that could affect stability
- Charter fishing boats: Most 6-pack OUPV operations with 7+ passengers require a stability letter
What the Stability Letter Specifies
- Maximum passenger count for each operating condition
- Passenger distribution: How many may be on deck, below, forward, aft
- Maximum cargo weights and approved locations
- Fuel and water load conditions at departure and on arrival
- Free surface effect limitations (partially filled tanks)
- Prohibited conditions: Loading scenarios not approved
Passenger Crowding Scenario — Classic Exam Question
The exam will present a scenario like this:
"Your vessel's stability letter allows 20 passengers with no more than 10 on the bow deck. All 20 passengers move to the bow to watch a whale. What should you do?"
Free surface effect: Partially filled tanks reduce stability because the liquid shifts to the low side. This is why stability letters specify minimum fuel loads and prohibit operating with certain tanks partially filled.
Key Term: GM (Metacentric Height)
GM is the distance between the vessel's center of gravity (G) and the metacenter (M). A positive GM means the vessel will self-right after heeling — the vessel is stable. A larger GM means stiffer stability (quicker righting) but a harder ride. A smaller positive GM means more tender stability. A negative GM means the vessel is unstable and will capsize. The stability letter ensures the vessel maintains adequate positive GM in all approved loading conditions.
7. Manning Requirements
The COI specifies the minimum safe manning for an inspected vessel. This includes the grade of license required, the number of licensed officers, and the deck/engine crew complement.
| Position | License Required | Notes |
|---|---|---|
| Master | OUPV (6-pack) or Master, appropriate tonnage and route | Must hold license matching or exceeding vessel tonnage and geographic route on COI |
| Mate | Mate license appropriate to vessel tonnage | Required when vessel carries more than 12 passengers on ocean routes, or when COI specifies |
| Designated Duty Engineer | Engineer license or Qualified Member Engine Department (QMED) | Required on vessels with propulsion machinery above certain horsepower thresholds |
| Able Seaman (AB) | AB endorsement | Required on inspected vessels above certain size; deck watch requirement |
| Ordinary Seaman (OS) | No specific license; TWIC required | May count toward crew complement on smaller vessels |
Minimum Safe Manning Document
The Minimum Safe Manning Document (MSMD) is incorporated into the COI or issued separately. It specifies the absolute minimum crew required to operate the vessel safely. The master may not depart with fewer than the minimum specified crew aboard.
- Crew counts by position
- Required license grades by position
- Watchstanding requirements (6-hour on / 6-hour off)
- Engineer requirements based on HP thresholds
Watchstanding Hours
Federal regulations limit watchstanding hours to protect against fatigue-related incidents. Key rules for licensed officers on inspected vessels:
- Maximum watch: 8 hours in any 24-hour period without relief
- Minimum rest: 8 consecutive hours off watch before returning to duty
- Emergency exception: Watch may be extended during emergency operations
- STCW vessels: STCW hours of rest requirements apply — 10 hours minimum rest in any 24-hour period
License Tonnage Must Match or Exceed the Vessel
A master's license has a tonnage limitation. A Master 50 GT license cannot legally serve as master of a 75 GT inspected vessel. The license must match or exceed the vessel's gross tonnage AND the route authorization on the COI. A 100 GT license on a coastwise route covers any inspected vessel under 100 GT on coastwise waters. Verify both tonnage and route endorsement before assuming a license is sufficient.
8. Equipment Requirements for Inspected Vessels
Inspected vessels must carry equipment specified on the COI. The type and quantity depends on the subchapter, route, and passenger capacity.
| Equipment Category | Subchapter T Requirements | Subchapter K Additions |
|---|---|---|
| Lifesaving Appliances (LSA) | Life preservers for each person aboard; ring buoys; inflatable or rigid liferafts or lifeboats per route | Same plus additional immersion suits if operating in cold waters; more rigid survival craft requirements |
| Fire Detection & Suppression | Fixed CO2 or FM-200 systems in engine spaces; fire extinguishers per 46 CFR; smoke detectors in accommodation spaces | Enhanced fixed fire suppression; sprinkler systems in passenger spaces for larger vessels; fire pumps and hose stations |
| EPIRB | Category I 406 MHz EPIRB required on ocean and coastwise routes; Category II acceptable on inland/protected waters in some cases | Same as Subchapter T; EPIRB must be registered with NOAA |
| VHF-FM Radio | Required on all inspected vessels; DSC controller required on vessels over certain sizes | Same; GMDSS requirements may apply depending on route |
| Navigation Equipment | Running lights, radar (on certain routes), compass, depth sounder per route requirements | Enhanced radar, electronic charts, AIS on certain vessels |
| First Aid | First aid kit; vessels on longer routes may require AED | Enhanced medical kit; AED required; crew trained in first aid |
EPIRB Requirements — Detail
- Category I EPIRB: Automatically activates when submerged; float-free bracket required on ocean/coastwise routes
- Category II EPIRB: Manually activated or water-activated; acceptable on some protected water routes
- 406 MHz required: All EPIRBs must operate on 406 MHz for COSPAS-SARSAT satellite detection
- NOAA registration: Every EPIRB must be registered with NOAA — registration links the EPIRB to vessel and owner data for SAR response
- Battery expiration: EPIRB batteries have expiration dates stamped on the unit; expired batteries are a COI violation
Fire Suppression — Inspected Vessels
- Fixed systems: Engine spaces on inspected vessels require fixed CO2, FM-200, or equivalent suppression systems
- Portable extinguishers: Type B-I and B-II extinguishers at required stations per 46 CFR 181
- Smoke detectors: Required in accommodation and passenger spaces
- Fire pumps: Inspected vessels on ocean routes must have a powered bilge/fire pump
- Crew training: Crew must be trained in fire suppression procedures; drills required
Life Jacket (PFD) Requirements
Inspected vessels must carry Coast Guard-approved Type I, II, or III life preservers for every person aboard (passengers plus crew). The number of PFDs must equal or exceed the total person capacity specified on the COI. The exam tests this: if the COI authorizes 25 passengers and 3 crew, you need at least 28 USCG-approved life preservers.
9. Subchapter M — Towing Vessels
Subchapter M (46 CFR Parts 136–144) was finalized in 2016 and brought towing vessels — tugboats, towboats, and articulated tug-barges — under mandatory USCG inspection for the first time. It took full effect in 2019.
Who Subchapter M Covers
- Tugboats: Harbor tugs, ocean-going tugs
- Towboats: Inland river push-boats
- Articulated Tug-Barges (ATB): Integrated tug-barge units
- Minimum length: 26 feet or more
- Exclusions: Recreational vessels, SECU (single engine, crew under 6, coastwise routes — some exemptions apply)
Two Compliance Pathways
Towing vessel operators choose one of two compliance options:
Safety Management System (SMS) Requirement
All towing vessels subject to Subchapter M must have a documented Safety Management System (SMS). The SMS is a formal, written system for managing safety operations. It must address:
- ▶Vessel maintenance procedures
- ▶Navigation safety procedures
- ▶Emergency response plans
- ▶Incident reporting and investigation
- ▶Crew training and drills
- ▶Equipment inspection schedules
- ▶Drug and alcohol policies
- ▶Watchstanding and fatigue management
Towing Vessel Examination (TVE)
For vessels choosing the USCG inspection pathway, the primary inspection tool is the Towing Vessel Examination. The USCG marine inspector conducts a comprehensive examination covering hull, machinery, safety equipment, SMS documentation, crew records, and operational procedures. Upon satisfactory completion, the vessel receives a Certificate of Inspection (COI) specific to Subchapter M. Vessels must maintain compliance between scheduled examinations.
10. Port State Control (PSC)
Port State Control is the mechanism by which nations inspect foreign-flagged vessels visiting their ports to verify compliance with international maritime conventions.
Legal Basis for PSC
- SOLAS: Safety of Life at Sea — construction, equipment, stability, fire protection, LSA
- MARPOL: Marine pollution prevention — oil record book, garbage management, ballast water
- STCW: Standards of Training, Certification and Watchkeeping — crew credentials and hours of rest
- MLC 2006: Maritime Labour Convention — crew living conditions, wages, and welfare
- ISM Code: International Safety Management — SMS documentation on SOLAS vessels
What PSC Inspectors Check
- Valid flag state certificates (SOLAS safety certificate, load line certificate, MARPOL certificate)
- ISM certificate (Safety Management Certificate) and Document of Compliance
- Crew STCW certificates — valid, appropriate for position, flag state endorsed
- Hours of rest records (STCW compliant)
- Lifesaving equipment — condition, hydrostatic releases, EPIRB registration
- Fire suppression systems — service dates, pressure gauges
- Navigation equipment — ECDIS, radar, GMDSS operational
PSC Deficiency Categories
| Category | Description | Detention? |
|---|---|---|
| Category 1 — Minor | Technical deficiency with no immediate safety concern; corrected before next port | No |
| Category 2 — Significant | Deficiency affecting safety or pollution prevention; must be corrected before departure or USCG satisfied with interim measures | Possible |
| Category 3 — Detention-Worthy | Deficiency posing serious danger to vessel, crew, passengers, or environment | Yes — cannot depart until corrected |
| Outstanding Deficiency | Deficiency from a prior PSC inspection not corrected; carries over and triggers heightened targeting | Likely |
Targeting System — Why Prior Detentions Matter
PSC authorities (including the USCG) use a targeting system to prioritize which vessels get boarded. Factors that increase targeting score include: prior detentions, outstanding deficiencies from previous inspections, flag state performance, classification society performance, vessel age, vessel type (tankers score higher), and time since last inspection. A vessel that has been detained in any port worldwide will face heightened scrutiny at every subsequent port call until its record improves.
Paris and Tokyo MOU — Regional PSC Cooperation
Port State Control is organized regionally through Memoranda of Understanding (MOUs). The Paris MOU covers European and North Atlantic ports. The Tokyo MOU covers Asia-Pacific ports. The USCG operates as part of the U.S. national PSC regime. Deficiency records are shared among MOU member states — a detention in Rotterdam is visible to USCG inspectors in New York. The exam may reference Paris or Tokyo MOU in context questions about international vessel inspections.
11. USCG Documentation vs. State Registration
Federal documentation and state registration are two different systems. Understanding which is required — and what endorsements are available — is tested on the captain's exam.
USCG Federal Documentation (COD)
- Required when: Vessel is 5 net tons or more AND used in coastwise trade, fisheries, or on federal waters where documentation is required
- Certificate of Documentation (COD): The official federal document; replaces state registration for documented vessels
- Number displayed: Official number carved or permanently affixed in structural part of hull (not painted on)
- Name and hailing port: Required on exterior of documented vessels
- Annual renewal: COD must be renewed annually
State Registration
- Required for: Vessels not federally documented; most recreational vessels
- Numbers displayed: State-assigned registration numbers (e.g., FL 1234 AB) on bow
- Stickers: Current validation sticker displayed near registration number
- Limitation: State registration does not authorize coastwise trade or fisheries
- If documented: State registration is NOT required (federal documentation is sufficient)
Certificate of Documentation Endorsements
| Endorsement | Requirement | Notes |
|---|---|---|
| Coastwise Trade | Vessel must be U.S.-built, U.S.-owned, and U.S.-flagged; allows carriage of passengers or cargo between U.S. ports (Jones Act) | Foreign-built vessels cannot receive coastwise endorsement even with U.S. ownership |
| Fisheries | U.S.-built or eligible alien-built vessel; used for fishing in U.S. EEZ | Separate from coastwise; a vessel may hold both |
| Registry | International trade; no U.S.-built requirement | Vessels in registry cannot engage in coastwise trade |
| Recreation | Any U.S.-owned vessel not used for hire | No commercial activity; exempt from most inspection requirements |
Jones Act — The Coastwise Trade Law
The Merchant Marine Act of 1920 (Jones Act) requires that vessels carrying passengers or cargo between U.S. ports be U.S.-built, U.S.-owned, U.S.-flagged, and U.S.-crewed. This is the coastwise trade requirement. A foreign-built vessel, even if U.S.-owned and U.S.-flagged, cannot receive a coastwise endorsement and cannot legally carry passengers or cargo between two U.S. ports. The exam tests Jones Act requirements in the context of documentation endorsements.
12. Practice Problems with Solutions
Work through these exam-style questions. Click each to reveal the answer and explanation.
Q1 — A vessel is 85 gross tons and carries 160 passengers for hire on domestic voyages. Which USCG subchapter applies?
Subchapter K (46 CFR Parts 114–122) applies to small passenger vessels under 100 gross tons carrying more than 150 passengers on domestic voyages. This vessel is 85 GT (under 100 GT threshold) and carries 160 passengers (more than 150). Subchapter T would apply if the passenger count were 150 or fewer. The vessel is under 100 GT, so Subchapter H does not apply.
Q2 — Where must the Certificate of Inspection be posted on a passenger vessel?
46 CFR requires the COI to be posted in a conspicuous place that is accessible to passengers. It is not sufficient to simply keep the COI in the captain's cabin or in a file — it must be displayed where passengers can see it. Common locations: gangway area, main salon, or near the helm on smaller vessels. Both "conspicuous" and "accessible to passengers" are required elements.
Q3 — A steel-hulled inspected passenger vessel last had a drydock inspection 4 years ago. Is it overdue?
Steel-hulled (and fiberglass-hulled) inspected vessels require drydock haul-out inspection every5 years. At 4 years, the vessel is not yet overdue. If the hull were wooden, the requirement would be every 2 years — and at 4 years the vessel would be significantly overdue. Always consider hull material when answering inspection frequency questions.
Q4 — Your vessel's stability letter allows a maximum of 8 passengers on the bow deck at a time. You currently have 14 passengers on the bow deck. What is your immediate responsibility?
The master is responsible for maintaining the vessel within the approved conditions specified in the stability letter at all times. With 14 passengers on the bow where only 8 are approved, the vessel may be operating outside its approved stability envelope. The master must immediately redistribute passengers — not after the next stop, not after the current maneuver. Immediately. This protects vessel stability and avoids regulatory violation. The exam frames this as a judgment question: the correct answer is always "restore the approved condition immediately."
Q5 — A vessel operating under Subchapter M wants to use a third-party organization for compliance. What must the TPO be?
Subchapter M allows towing vessels to comply through either direct USCG inspection or through a USCG-approved Third-Party Organization (TPO). The key word is USCG-approved — not just any classification society or surveyor. The USCG maintains a list of approved TPOs. The TPO conducts surveys equivalent to the USCG inspection and issues its own certificates, which the USCG accepts as evidence of compliance. The SMS must still be maintained regardless of which pathway the operator chooses.
Q6 — You are transiting the North Atlantic in January. The vessel's Plimsoll mark shows the waterline is at the Summer (S) mark. Is this a violation?
In January, the North Atlantic falls under the Winter North Atlantic (WNA) zone — the most restrictive load line zone. The WNA mark is below the Summer (S) mark, meaning the vessel must sit higher in the water (carry less cargo/load) than the Summer mark allows. If the waterline is at the Summer mark, the vessel is overloaded relative to the WNA requirement. This is a violation of load line regulations regardless of how well the vessel appears to be handling the conditions. Load line marks exist precisely because winter North Atlantic conditions demand extra freeboard safety margin.
Q7 — A USCG PSC inspector boards a foreign-flagged vessel and finds the crew's STCW certificates are from a flag state not in compliance with STCW. What can the USCG do?
STCW compliance is a PSC inspection priority. If crew members hold STCW certificates from a flag state that has not been recognized by the inspecting port state as STCW-compliant (or if the certificates themselves are fraudulent, expired, or not properly endorsed by the flag state for service on that vessel), this is a detention-worthy deficiency. Crew without valid STCW credentials are legally unqualified to stand watch — the vessel cannot safely depart. The USCG can issue a control action (detention) until the vessel demonstrates it has qualified watchkeepers aboard.
Q8 — A U.S. owner purchases a Canadian-built sailboat and wants to operate it as a passenger vessel between Miami and Key West. Can it receive a coastwise trade endorsement?
The Jones Act (Merchant Marine Act of 1920) requires that vessels in coastwise trade be U.S.-built, U.S.-owned, U.S.-flagged, and U.S.-crewed. A Canadian-built vessel fails the U.S.-built requirement regardless of who owns it or what flag it flies. Foreign-built vessels can receive a registry endorsement for international voyages, but cannot receive a coastwise endorsement to carry passengers or cargo between two U.S. domestic ports. This is a hard rule with very limited exceptions (certain pre-WWII vessels, specific legislative waivers).
Q9 — Your inspected passenger vessel's COI authorizes "protected waters" operation. A passenger asks you to take the group through an inlet and 2 miles offshore to a dive site. What should you do?
The COI route authorization is a hard legal limit. A vessel authorized for "protected waters" cannot legally carry passengers on ocean or coastwise waters, even for 2 miles. The seaworthiness of the vessel and the calm weather conditions are irrelevant — the authorization does not extend to offshore waters. Operating passengers outside the authorized route exposes the master to license suspension or revocation and the operator to significant civil penalties. The correct answer is always to stay within COI-authorized waters.
Q10 — An uninspected passenger vessel (UPV) is carrying 10 passengers for hire on protected waters. Is a stability letter required?
Uninspected passenger vessels carrying between 7 and 12 passengers for hire are required to have a stability letter issued by the USCG. The stability letter establishes the safe operating conditions for that vessel with that passenger load. Even though the vessel is "uninspected" (no COI), the stability letter requirement still applies. The master must operate within the conditions specified in the stability letter. Carrying more than 12 passengers for hire on protected waters would require the vessel to be inspected (COI) rather than operating as a UPV.
Quick Reference — Key Numbers to Memorize
Frequently Asked Questions
What is the difference between an inspected and an uninspected vessel?
An inspected vessel carries a Certificate of Inspection (COI) issued by the USCG after meeting all applicable construction, equipment, and manning standards. Uninspected vessels are not required to have a COI — generally recreational vessels and certain small commercial vessels. The trigger for inspection is typically carrying passengers for hire or operating as a commercial vessel above a tonnage threshold. Under 46 CFR Subchapter T, small passenger vessels under 100 gross tons carrying up to 150 passengers on domestic voyages are inspected vessels.
What does a Certificate of Inspection (COI) specify?
A COI specifies: (1) the route or geographic operating area the vessel is authorized to operate; (2) the maximum number of passengers and crew; (3) manning requirements including license grades; (4) the number, type, and arrangement of survival craft and fire suppression equipment; (5) minimum freeboard; and (6) the date of the next required inspection. The COI must be posted in a conspicuous place accessible to passengers.
When does Subchapter T apply vs. Subchapter K?
Subchapter T (46 CFR Parts 175-185) applies to small passenger vessels under 100 gross tons carrying up to 150 passengers on domestic voyages. Subchapter K (46 CFR Parts 114-122) applies to small passenger vessels under 100 gross tons carrying more than 150 passengers. Both subchapters require USCG inspection and a COI. Vessels over 100 gross tons fall under Subchapter H (passenger vessels) or other applicable regulations.
When is a load line certificate required?
Load line requirements apply to most U.S. vessels over 79 feet in length operating on international voyages, and to certain vessels on domestic voyages depending on service. The load line certificate specifies the minimum freeboard — the distance from the waterline to the main deck. The Plimsoll mark on the hull shows the maximum permitted load waterlines for different ocean zones and seasons. Small passenger vessels under Subchapter T are exempt from load line requirements.
What is a stability letter and when is it required?
A stability letter (or stability booklet for larger vessels) is issued by the USCG after stability testing or calculations. It establishes approved loading conditions — maximum passenger counts, weight distribution, and permitted cargo configurations. Stability letters are required for uninspected passenger vessels (UPVs) carrying 7 to 12 passengers and for inspected vessels where stability is a design concern. The master must operate within the approved conditions specified in the stability letter.
What are the inspection intervals for inspected vessels?
Inspected passenger vessels require: (1) an annual inspection of the entire vessel; (2) a biennial (every two years) out-of-water inspection for hull examination; and (3) a drydock or haul-out inspection every five years for most vessels (every two years for wooden-hulled vessels). Some vessels may qualify for an underwater survey by a USCG-approved dive team in lieu of drydocking. The COI will note the due dates for each inspection type.
What is Port State Control and what happens during a PSC inspection?
Port State Control (PSC) is the authority of a flag state to inspect foreign-flagged vessels in its ports for compliance with international conventions (SOLAS, MARPOL, STCW, MLC). In U.S. ports, the USCG conducts PSC inspections. Inspectors check certificates, crew credentials, safety equipment, and operational readiness. Deficiencies are categorized and documented. Serious deficiencies can result in detention — the vessel may not depart until deficiencies are corrected. Detention can trigger a targeting flag that causes heightened scrutiny on future port calls.
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