A Jones Act ship is a vessel that meets four federal conditions at once: it was built in the United States, is owned by U.S. citizens, is crewed predominantly by Americans, and flies the U.S. flag with a coastwise endorsement issued by the Coast Guard. Only ships meeting all four may legally carry cargo or passengers between two points inside the United States. The rule comes from the Merchant Marine Act of 1920, and the eligibility standards live in 46 U.S.C. § 12112.
The Four Requirements a Vessel Must Meet
Built in the United States
Federal regulations set two conditions for a domestic build: every major component of the hull and superstructure must be fabricated in the United States, and the ship must be assembled entirely in a U.S. shipyard.1eCFR. 46 CFR Part 67 – Documentation of Vessels Fabricating a hull overseas and finishing it stateside does not count. And a qualifying ship that later undergoes major reconstruction in a foreign yard loses its coastwise eligibility permanently. Once gone, that status cannot be restored.
Domestic construction is expensive. U.S.-built commercial vessels run roughly four to five times the cost of comparable ships built in South Korea, China, or Japan, and that premium is reflected in shipping rates on Jones Act routes.
Owned by U.S. Citizens
Ownership rules come from 46 U.S.C. § 12103. An individual owner must be a U.S. citizen. A corporate owner must be incorporated in the United States, with both the CEO and the chairman of the board holding citizenship, and a majority of the directors needed for a quorum must also be citizens.2Office of the Law Revision Counsel. 46 USC 12103 – General Eligibility Requirements For partnerships and similar entities, the controlling interest must sit with U.S. citizens. These conditions are continuing obligations, not a one-time filing; the ownership profile must remain compliant for as long as the ship carries a coastwise endorsement.
Crewed by American Mariners
The crew rules in 46 U.S.C. § 8103 are stricter for officers than for the rest of the crew. The master, chief engineer, radio officer, and every officer in charge of a navigation or engineering watch must be U.S. citizens; lawful permanent residents do not qualify for these positions. Among unlicensed crew, every seaman must be a citizen or a permanent resident, and no more than 25 percent may be permanent residents.3Office of the Law Revision Counsel. 46 USC 8103 – Citizenship Requirements All crew members must hold valid Merchant Mariner Credentials from the Coast Guard.
Documented Under the U.S. Flag
Registration happens at the National Vessel Documentation Center, the Coast Guard office that maintains the federal registry of U.S. vessels.4United States Coast Guard. National Vessel Documentation Center A successful application produces a Certificate of Documentation with a coastwise endorsement, which is the formal proof that the ship satisfies all four requirements and may operate on domestic routes.5Office of the Law Revision Counsel. 46 USC 12112 – Coastwise Endorsement Without that endorsement on the certificate, the ship cannot legally move goods or passengers between U.S. points.
What Vessels the Law Covers
Every commercial vessel moving between two domestic points falls under the law, regardless of size or function. Container ships and oil tankers are the visible core, but the reach is much wider. Tugboats and barges face parallel coastwise rules on towing between U.S. ports and handle enormous volumes on inland waterways, rivers, and harbor approaches. Dredging vessels maintaining navigation channels are covered. So are offshore supply vessels that run personnel and equipment to oil rigs and wind farms inside the exclusive economic zone. Specialized ships for cable laying, subsea construction, and heavy-lift work are covered too, and even a non-self-propelled barge counts when it carries commercial cargo between domestic points.
Which Routes Trigger the Law
Under 46 U.S.C. § 55102, no vessel may transport merchandise between points in the United States without a coastwise endorsement. A “U.S. point” includes every port in the contiguous states plus Alaska, Hawaii, Puerto Rico, Guam, and American Samoa.6Maritime Administration. Domestic Shipping Oil from Houston to San Juan, building materials from Seattle to Anchorage — both must move on a Jones Act ship.
Sending cargo through a foreign port is not a loophole. The statute prohibits transporting merchandise between U.S. points “either directly or via a foreign port.”7Office of the Law Revision Counsel. 46 USC 55102 – Transportation of Merchandise Loading in Miami, stopping in the Bahamas, and delivering to New York on a foreign-flagged ship is still a violation. If the origin and final destination are both in the United States, the law applies to the whole voyage.
The U.S. Virgin Islands are the notable exception. The Merchant Marine Act excluded the territory from all coastwise laws unless the president extends them there by proclamation, and no president has ever done so.8U.S. Department of the Interior. Application of US Coastal Laws to Virgin Islands Foreign-flagged vessels can freely carry cargo and passengers between the mainland and the USVI.
Passenger Ships Follow a Separate Law
Passengers are governed by a companion statute, the Passenger Vessel Services Act of 1886, now at 46 U.S.C. § 55103. It applies the same basic restriction: a passenger vessel moving people between two U.S. ports must be coastwise-qualified.9Office of the Law Revision Counsel. 46 USC 55103 – Transportation of Passengers The statutory penalty is $300 per passenger, adjusted for inflation to $996 per passenger for violations after November 2015.10U.S. Customs and Border Protection. The Jones Act and The Passenger Vessel Services Act
Since virtually no large cruise ships are U.S.-built and U.S.-crewed, the industry works around this by routing through foreign ports. A round-trip cruise leaving and returning to the same U.S. port needs only one foreign stop. A repositioning cruise between two different U.S. ports must call at a “distant” foreign port, meaning one outside North America, Central America, Bermuda, the Bahamas, and the Caribbean (Aruba, Bonaire, and Curaçao are treated as distant). This is why Alaska cruises out of Seattle often end in Vancouver, and why ships sailing between the East Coast and Hawaii route through distant stops.
How the Rules Work for Offshore Wind
Offshore wind construction creates a compliance puzzle. Carrying turbine components, foundation sections, or scour protection from a U.S. port to an offshore site counts as moving merchandise between U.S. points and requires a Jones Act vessel.11Congress.gov. Offshore Energy: Vessel and Crew Nationality Requirements U.S. Customs and Border Protection has long read the law to allow foreign-flagged vessels to perform construction at a fixed offshore location, provided they don’t also carry the components from shore.
The workaround is a two-vessel system. A Jones Act feeder barge moves the blades, nacelles, or tower sections from port to the site. A foreign-flagged installation vessel, usually a large jack-up crane ship, lifts the pieces off the feeder and installs them on the foundation.11Congress.gov. Offshore Energy: Vessel and Crew Nationality Requirements No U.S.-flagged heavy-lift installation vessels currently exist at the scale modern turbines require, so the split-operation approach is the standard.
Waivers Are Rare and Narrow
Under 46 U.S.C. § 501, the federal government can waive coastwise restrictions temporarily when national defense requires it. There are two pathways.
The Secretary of Defense can request a waiver if it is “necessary in the interest of national defense to address an immediate adverse effect on military operations.” Congress tightened the language in 2021 by adding the requirement of an immediate military impact rather than a general national defense concern. Within 24 hours of the request, the Secretary must send a written explanation to congressional committees confirming that qualified U.S. vessels are insufficient to meet the need.12Office of the Law Revision Counsel. 46 USC 501 – Waiver of Navigation and Vessel-Inspection Laws
The second pathway runs through the White House. The president must determine that a waiver is necessary for national defense, and the Maritime Administrator must find that Jones Act vessels are not available in sufficient numbers. This track also requires the waiver request to be posted on the CBP website before it takes effect.13U.S. Customs and Border Protection. Requests to Waive the Navigation Laws
In practice, waivers are unusual. They were issued after Hurricanes Katrina and Rita in 2005, during Hurricane Irma in 2017 (a seven-day waiver, later extended), and during Hurricane Harvey the same year. After Hurricane Maria hit Puerto Rico, the administration initially declined and then reversed course, issuing a 10-day waiver.
Penalties for Operating Without Qualification
U.S. Customs and Border Protection is the primary enforcement agency. CBP reviews vessel documentation, cargo manifests, and arrival data to confirm that every ship moving goods between U.S. ports carries the required endorsement.6Maritime Administration. Domestic Shipping
Cargo penalties are severe. Merchandise carried on a non-qualifying vessel is subject to seizure and forfeiture. Alternatively, the government can seek a monetary penalty equal to the value of the merchandise or the actual cost of transportation, whichever is greater.7Office of the Law Revision Counsel. 46 USC 55102 – Transportation of Merchandise On a tanker carrying tens of millions of dollars of crude oil, that number can be enormous. CBP guidance states that when a violation occurs for commercial convenience rather than a legitimate emergency, the agency does not cap the penalty. Where the violation was caused by a genuine safety emergency, the penalty is capped at $100,000.14U.S. Customs and Border Protection. Fines, Penalties, Forfeitures and Liquidated Damages
The Coast Guard handles the documentation side. Its officers keep the vessel registries current and check that crews hold valid credentials and that ownership has not shifted in ways that disqualify the ship. A violation can be caught at loading, in transit, or on arrival, and the financial exposure is calculated per voyage.
The Current Fleet
As of early 2024, the Maritime Administration counted roughly 92 large Jones Act-eligible vessels in the deep-draft fleet: about 40 containerships, 19 tankers, 18 vehicle carriers, 9 general cargo ships, 4 dry bulk carriers, and a handful of roll-on/roll-off and combination vessels. Thousands of smaller tugs, barges, and offshore supply boats operate under coastwise endorsements outside that deep-draft count. Those 92 ships serve a country with more than 95,000 miles of coastline and non-contiguous territories that depend on ocean shipping for nearly everything they consume.