Mostly because a US flag would bring US shipbuilding and US crewing rules. The flag country is mainly responsible for checking a ship's safety, and other countries' ports inspect it too. Whether a cruise company pays US tax on its shipping income depends mostly on where the parent company is incorporated.

Why a cruise from Miami has to stop in another country

If you have taken a week-long cruise from Miami, Seattle or another American port, the ship almost certainly called somewhere abroad : Cozumel in Mexico, Nassau in the Bahamas, Victoria in Canada. That stop is there partly because the law requires it.

A US law from 1886, the Passenger Vessel Services Act, says a ship may not carry passengers from one American port to another unless it is owned by Americans and documented for trade along the US coast. To get that document, a ship has to be built in the United States and fly the US flag. Almost no large cruise ship meets those conditions.

So a foreign-flagged ship that leaves Miami and brings its passengers back to Miami calls at a foreign port on the way. Alaska cruises that start and end in Seattle stop in British Columbia for the same reason. The foreign stop does not make every itinerary lawful, though. US customs rules distinguish nearby foreign ports from distant ones, and a stop at a nearby one generally still does not let a passenger board at one US port and leave the ship for good at another. What counts is where each passenger gets on and where they get off.

The one big cruise ship that flies the American flag

There is one large exception. Norwegian Cruise Line's Pride of America sails between the Hawaiian islands without ever calling at a foreign port. It can do this because it flies the US flag. A provision written specifically for this Hawaii service allowed the ship to be completed in a foreign shipyard and still be documented in the United States. It was not a general exception for foreign-built cruise ships.

The company's annual filing shows what comes with that flag. The ship answers to US agencies including the Coast Guard, the Food and Drug Administration and the Department of Labor, and its income is subject to US federal and state income tax. US law also requires the master and officers of a US-flagged ship to be American citizens, and on a US passenger ship at least 75% of the unlicensed crew must be US citizens or permanent residents.

That is the plain reason so few cruise ships sailing from American ports fly the American flag. For a ship carrying passengers between US ports, the flag brings American shipyards, American crews and American rules with it.

What a ship's flag actually decides

Every ship is registered in one country, called its flag state. Under international law, the flag state carries the main responsibility for the ship wherever it sails, whatever the owner's nationality or the ship's home port. That responsibility covers certification and the ship's technical, administrative and social matters. The flag state is not the only authority, however. International conventions apply, and the countries whose ports the ship visits can inspect it as well.

Carnival's annual report for its 2025 financial year says its ships are flagged in the Bahamas, Bermuda, Italy, the Netherlands, Panama and the UK. It says these flag states regulate health, environmental, safety and security matters for guests, crew and ships through international conventions, and that their own inspectors check compliance.

Royal Caribbean's ships are registered in the Bahamas, Cyprus and Malta, and in Ecuador for ships sailing in the Galapagos. Norwegian's are registered in the Bahamas and the Marshall Islands, apart from Pride of America.

Look at what is missing. Liberia, one of the three countries people name, does not appear in the flag lists these three companies give in their filings. That is a finding about these filings, not proof that no cruise ship anywhere flies the Liberian flag. Liberia turns up somewhere else.

The tax break follows the company, not the flag

Many people assume a cruise ship registers in Panama or the Bahamas to avoid tax. In the filings of the three big cruise companies listed in New York, the US tax exemption on their shipping income depends on a different choice : the country where the parent company is incorporated.

Section 883 of the US tax code exempts a foreign company's income from operating ships internationally, on two conditions that matter here. The country where the company is organized must give American shipping companies the same exemption, and the company's shares must trade regularly on an established market such as the New York Stock Exchange. Those tests are about the company, not the flag on the ship.

Royal Caribbean, headquartered in Miami, is a Liberian corporation, and its filing says it and its ship-owning subsidiaries qualify for Section 883 because they are incorporated in Liberia. Norwegian Cruise Line Holdings is a Bermuda company and makes the same claim on the basis of Bermuda. Carnival was a Panama corporation until 7 May 2026, when it completed a move of its incorporation to Bermuda and became Carnival Corporation Ltd., keeping its headquarters in Miami. Its 2025 annual report was filed before that move.

So Liberia and Panama sit in this story mostly as places where cruise companies have been incorporated, not as the flags on the stern. Incorporation does not settle every tax question on its own, either. Norwegian's filing says the income of its US-flagged ship is taxed in the US. The Treasury rules say selling or arranging single-day shore excursions is not part of operating ships internationally, so that income falls outside the exemption. How any company's income is taxed still depends on its own facts.

The flag on the ship and the company's legal home are separate choices · Where each company's ships are flagged and where its parent company is incorporated, from each company's 2025 annual filing · Company · Ships flagged in · Parent company incorporated in · Carnival · Royal Caribbean · Norwegian — Where each company's ships are flagged and where its parent company is incorporated, from each company's 2025 annual filing

Why Liberia and Panama lead world shipping anyway

The countries in the question are not random. Registers that accept ships whose owners are based elsewhere, often called open registries or flags of convenience, dominate merchant shipping as a whole. On 1 January 2025, according to the Review of Maritime Transport 2025 from UNCTAD, the UN's trade and development body, ships flagged in Liberia held 17.4% of the world's carrying capacity, Panama 15.2% and the Marshall Islands 12.5%, together 45.1%.

Those figures measure the entire merchant fleet by deadweight tonnage, roughly how much cargo a ship can carry, so they are weighted toward cargo ships such as tankers, bulk carriers and container ships. They are not cruise figures, and they cannot show how many cruise ships fly the Liberian or Panamanian flag. In the cruise companies' own filings, the one flag all three share is the Bahamas.

Three open registries carry 45.1% of world shipping capacity · Share of the world merchant fleet's carrying capacity (deadweight tonnage) by flag, 1 January 2025 · Liberia · Panama · Marshall Islands · 17.4% · 15.2% · 12.5% · All other flags · UNCTAD figures for the whole merchant fleet, weighted to — Share of the world merchant fleet's carrying capacity (deadweight tonnage) by flag, 1 January 2025

The fare is only part of what a cruise earns

The business has one more layer people rarely see. Carnival's annual report for its 2025 financial year says 34% of its cruise revenues came from onboard and other goods and services : drinks, internet, casino gaming, spas, shore excursions, specialty restaurants, shops and photos. That was about $9.2 billion.

Many of these can be bought before boarding, singly or as packages. By that report, tickets made up roughly the other two thirds of what a cruise brings in.

A third of Carnival's cruise revenue came from more than the fare · Carnival's cruise revenues in its 2025 financial year, split by source · Onboard and other · 34% · Tickets, roughly two thirds · Onboard and other covers drinks, internet, casino, spas, excursions, dining, shops and photos : about $ — Carnival's cruise revenues in its 2025 financial year, split by source

Carnival Corporation Form 10-K, fiscal 2025

Two choices, both legal, often mistaken for one

Registering ships abroad and incorporating the parent company abroad are both legal, and the companies describe both openly in their filings. They are separate decisions that touch different things.

The flag decides which country carries the main responsibility for a ship's safety, certification and crew rules, and a ship without the US flag is not bound by US shipbuilding and crewing requirements. It is still inspected in the ports it visits, including American ones. Where the parent company is incorporated goes a long way toward deciding whether its international shipping income is exempt from US tax. The country painted on the stern tells you who is mainly responsible for the ship. It does not tell you where the company pays tax.

Why are so many cruise ships registered in Panama, Liberia or the Bahamas?

Alpha · deepseek-v4-pro

The short version: these are open registries — often called “flags of convenience” — and a ship’s flag is its governing legal jurisdiction. For cruise ships, the reason not to fly the US flag is mainly operating cost and legal constraint, not simple tax avoidance. 1. A US flag drags in US-built ships and US crews. Under the Passenger Vessel Services Act, 46 U.S.C. § 55103, a foreign-flagged ship cannot carry passengers from one US port to another unless it is US-owned and holds a coastwise endorsement. Getting that endorsement requires the vessel to be built in the United States (46 U.S.C. § 12112). On top of that, US-documented passenger vessels must have American officers and a crew made up mostly of US citizens or lawful permanent residents (46 U.S.C. § 8103). Almost no modern large cruise ship is built in the US, and most are crewed by international workers at non-US wage scales. That is why a cruise from Miami or Seattle that is foreign-flagged must call at a foreign port — Nassau, Cozumel, Victoria — so the voyage becomes “international” rather than domestic coastwise trade. 2. The flag decides whose rules apply on board. Panama, Liberia and the Bahamas are open…

Beta · gpt-6-sol

The main reason is that a ship’s flag and its owner’s home country need not be the same. Open registries let cruise operators register ships abroad. The flag state has primary responsibility for the ship’s certification and enforcement of international maritime rules, while its crewing rules can differ from those for a US-documented ship. That can give an operator more flexibility over how it builds and staffs its fleet. It does not mean the ship escapes safety rules: international conventions apply, and countries whose ports it visits can inspect it too. (imo.org) For cruises involving US ports, a second distinction matters. US law generally reserves transportation of passengers between US ports to vessels qualified for the coastwise trade. A coastwise endorsement ordinarily requires a US-built vessel; US-documented vessels also face citizenship requirements for key officers and crew, subject to statutory exceptions. A foreign-flag ship can instead run an itinerary that meets the rules for calling abroad. But the details matter: a nearby forei…

Gamma · gemini-3.1-pro

I have reviewed the manuscript and checked the specific items requested by the editor. Here is what I found regarding the claims, the required fact-checks, and the manuscript's overall premise. 1. Pride of America’s crewing requirements The manuscript claims the ship must carry American officers and a mostly American crew. This is supported by 46 U.S.C. § 8103, which mandates that only a citizen of the United States may serve as master, chief engineer, or officer on a documented vessel, and that at least 75 percent of the unlicensed seamen on a U.S. passenger vessel must be U.S. citizens or permanent residents. *Source: https://www.law.cornell.edu/uscode/text/46/8103* 2. Pride of America’s foreign shipyard exception The manuscript correctly notes that a special provision allowed the ship to be finished abroad and still fly the U.S. flag. This is found in the "Hawaii Cruise Ship Provision" of the Consolidated Appropriations Resolution, 2003 (Public Law 108-7, Section 211, 117 Stat. 79), which explicitly allowed two partially completed ships contracted in a U.S. yard to be completed outside the U.S. and documented under the U.S. flag for Hawaii service. *Source: https://w…

Researcher · gpt-6-luna

Researcher’s fact-check Bottom line: The manuscript’s central distinction holds: registering a ship and incorporating its parent company are separate choices with different legal effects. The draft does, however, overstate what a foreign port call does under U.S. law, and its “the flag decides whose rules apply” language needs qualification. Claims checked - Open registries and flag-state responsibility: The IMO explains that an open registry allows ships owned or controlled by foreigners to fly that country’s flag. Under international law, the flag state is responsible for exercising jurisdiction and control over its ships, including on administrative, technical and social matters. That does not mean the flag state supplies every law that could apply: port-state rules and other applicable national or international requirements can also matter. Address: https://www.imo.org/en/ourwork/legal/pages/registration-of-ships-and-fraudulent-registration-matters.aspx Address: https://www.imo.org/en/ourwork/iiis/pages/survey-verification-certification.aspx - The Passenger Vessel Services Act (PVSA): The law bars carrying passengers between U.S. coastwise por…

The Arbiter · gpt-6-sol

The voices agree on the manuscript’s central distinction: a ship’s flag and its parent company’s place of incorporation are separate choices. The Researcher found support for that distinction in the company filings and the shipping-tax rules. The remaining question is how carefully the manuscript describes what each choice does. The clearest correction concerns foreign port calls. The manuscript’s Miami-to-Miami example is not a rule for every itinerary. Under the passenger-transport regulation, a call at a *nearby* foreign port does not generally allow a passenger to board at one US port and finish at another. The wording should follow the passenger’s actual embarkation and disembarkation, rather than say that a foreign stop simply makes the voyage lawful. (law.cornell.edu) There is also a meaningful difference in emphasis. Alpha and Gamma stress the costs and constraints associated with US-flag operation; Beta and the Researcher stress that foreign-flagged does not mean unregulated. The strongest challenge to the manuscript’s angle is its suggestion that the flag alone determines the law aboard or re…

The Arbiter's Final Verdict · gpt-6-sol

Verdict The manuscript’s central premise stands, but its opening answer is too categorical. Cruise operators use foreign registries because they allow ships owned elsewhere to fly their flags and offer flexibility in shipbuilding, crewing and operation. A US-flagged ship seeking to carry passengers between US ports ordinarily needs a coastwise endorsement, which generally requires US construction; US-documented passenger ships also face citizenship rules for officers and crew. But a foreign flag does not put a ship beyond safety regulation or US port inspections. (IMO; 46 USC §§ 12112, 8103) The question’s three countries need separating. In the cited filings, the Bahamas is a flag used by all three major cruise groups. Panama appears among Carnival’s ship flags, while Liberia appears as Royal Caribbean’s *place of incorporation*, not in the three groups’ disclosed flag-state lists. Liberia and Panama’s prominence in world shipping is real, but UNCTAD’s fig…