Cruise ships are required by law to dispose of most trash on land, not in the ocean
Cruise ships cannot legally dump regular trash overboard in most waters. International maritime law prohibits throwing garbage into the ocean within 12 nautical miles of shore, and within 25 nautical miles for some types of waste. Ships operating in U.S. waters face stricter rules: they must keep nearly all garbage on board and dispose of it at port, with only a few narrow exceptions for food waste in deep ocean.
That said, violations happen. The cruise industry has a documented history of illegal dumping. Ships have been caught discharging oily bilge water, plastics, and other waste directly into the sea. Fines have reached millions of dollars, and some cruise lines have pleaded guilty to environmental crimes. The rules exist because they work — when enforced, they keep the ocean cleaner than it would be otherwise.
Understanding what the law actually requires, what ships are caught doing, and what happens to waste that stays on board helps you see the real picture of cruise ship environmental impact.
Key Takeaways
- U.S. law requires cruise ships to keep garbage on board and dispose of it at port, with only food waste allowed overboard in deep ocean under strict conditions.
- International waters have looser rules, but ships still cannot dump most garbage within 12 to 25 nautical miles of any shore.
- Multiple cruise lines have been fined or prosecuted for illegally dumping waste, including oily water and plastics, showing that violations are real and documented.
- Waste that stays on board is typically incinerated at sea, recycled at port, or sent to landfills, depending on the material and the ship's practices.
- You can check a cruise line's environmental record and waste management plan before booking if this matters to your decision.
What the law actually says about ocean dumping
The main rule comes from MARPOL, an international treaty that sets standards for ship pollution. Under MARPOL, garbage cannot be thrown overboard within 12 nautical miles of land. For some waste types — like plastics and certain synthetics — the ban extends to 25 nautical miles. Food waste has a separate rule: it can be discharged in deep ocean (more than 12 nautical miles out) if it is ground to particles smaller than one inch.
U.S. law is stricter. The Act to Prevent Pollution from Ships requires vessels in U.S. waters to keep almost all garbage on board. Food waste is the only exception, and even that requires the ship to be at least 12 nautical miles from shore. Plastic, paper, metal, glass, and other solid waste must stay on the ship until it reaches port.
The rules vary slightly by region. Some areas, like the Mediterranean Sea and the North Sea, have designated "special areas" with even tighter restrictions. Cruise lines operating in those waters must follow the strictest standard that applies to any part of their route.
Documented cases of illegal dumping by cruise lines
Cruise companies have been caught breaking these rules repeatedly. In 2016, Royal Caribbean pleaded guilty to deliberately dumping oily bilge water and other waste into the ocean over a period of years. The company paid $18 million in fines and penalties. In 2019, Carnival Corporation (which owns Carnival, Princess, and Costa cruise lines) pleaded guilty to similar violations and paid $20 million.
These were not accidents. Internal documents showed that crew members were instructed to bypass pollution control systems and dump waste directly overboard. Ships were equipped with equipment to hide the dumping from detection systems. The violations occurred in U.S. waters, international waters, and near protected marine areas.
Smaller violations continue to surface. In 2022, a Disney Cruise Line ship was cited for dumping oily waste. In 2023, Norwegian Cruise Line faced a federal investigation for similar conduct. These cases show that despite the fines and legal consequences, some operators still view dumping as cheaper than proper disposal.
What happens to waste that stays on board
Cruise ships generate enormous amounts of garbage — a large ship can produce 8 to 10 tons of waste per day. Since most of it cannot go overboard, ships use three main methods to handle it: incineration, recycling, and storage for port disposal.
Incineration is the most common method for organic waste, paper, and other combustible materials. Ships have incinerators on board that burn garbage at high temperatures. The ash is either stored or discharged at sea under MARPOL rules, which allow ash from incinerators in certain conditions. This reduces the volume of waste but creates air emissions.
Recycling programs vary by cruise line. Some ships separate glass, metal, cardboard, and plastic for recycling at port. Others mix everything together. A few lines have committed to zero-waste goals, though none have fully achieved them. Most recycling still ends up in landfills or incinerators because the volume is too large and the sorting is incomplete.
Storage is used for waste that cannot be incinerated or recycled — mainly plastics and hazardous materials. Ships hold this waste in dedicated storage areas until they reach port, where it is offloaded to local waste management facilities. On long cruises, storage space can become a real constraint.
How cruise lines differ in their waste practices
Not all cruise lines handle waste the same way. Some have invested in better technology and transparency; others have minimal programs. A few lines publish annual environmental reports that detail how much waste they generate and where it goes. Most do not.
Disney Cruise Line and Cunard have made public commitments to reduce waste and increase recycling. They report their progress in sustainability reports. Royal Caribbean has a waste reduction program but has also faced the largest fines for violations. Carnival Corporation operates multiple brands with varying standards; some ships recycle more than others.
If environmental impact matters to you, you can request a cruise line's waste management plan before booking. Some lines will provide details about their incineration standards, recycling rates, and port disposal practices. Others will not. That difference itself tells you something about how seriously they take the issue.
The gap between rules and enforcement
The reason violations continue is that enforcement is weak. Ships operate in international waters where no single authority has jurisdiction. Port state control — inspections by authorities in ports where ships dock — is the main enforcement tool, but inspections are not routine and fines are often treated as a cost of doing business.
A cruise ship might be inspected once every few years. If caught, the fine is usually less than the money saved by illegal dumping over that period. For a large cruise line, an $18 million fine is significant but not catastrophic. The company pays, promises to do better, and the cycle continues.
Environmental groups have pushed for stricter monitoring, including real-time tracking of waste systems and surprise inspections. Some ports, particularly in Europe, have increased scrutiny. But in many parts of the world, oversight remains minimal.
What you can do as a passenger
You cannot control what a cruise line does with waste once you leave the ship, but you can make choices based on the information available. Before booking, check whether the cruise line publishes an environmental report. Ask the booking agent about the ship's waste management practices. Some lines will answer; others will deflect.
Once on board, participate in any recycling program the ship offers. Separate your trash as instructed. This does not may provide it will be recycled, but it increases the chance. Avoid single-use plastics when possible — bring a reusable water bottle and refuse plastic bags and straws.
If you witness or suspect illegal dumping, report it. Most cruise lines have internal reporting systems, and you can also contact the U.S. Coast Guard or the Environmental Protection Agency if the ship is in U.S. waters. International waters can be reported to the International Maritime Organization or to environmental groups that monitor shipping.
Frequently Asked Questions
Do cruise ships dump sewage in the ocean?
Cruise ships can discharge treated sewage in international waters under MARPOL rules, but U.S. law is stricter. Ships in U.S. waters must treat sewage to a high standard and can only discharge it beyond 3 nautical miles from shore. Some states, like California, have even tighter rules. Untreated sewage dumping is illegal everywhere.
What about food waste from the dining room?
Food waste is the one type of garbage ships can legally throw overboard, but only in deep ocean (at least 12 nautical miles from shore) and only if it is ground to particles smaller than one inch. Ships operating near coasts or in special areas must keep food waste on board instead. Most modern ships incinerate food waste anyway because it is easier than grinding and monitoring.
How do I know if a cruise line has been fined for dumping?
The U.S. Department of Justice publishes press releases about environmental prosecutions, and the EPA maintains a database of enforcement actions. You can search by company name. Environmental groups like Oceana and the Sierra Club also track cruise industry violations and publish reports. Some cruise lines voluntarily disclose their violations in sustainability reports.
Is the trash from my cabin recycled?
It depends on the ship and the material. Most cruise ships do not have the infrastructure to sort and recycle all passenger waste. Recyclables are often mixed with regular trash and incinerated. A few lines have dedicated recycling programs, but even those have low recovery rates because the volume is too large and sorting is incomplete.
What is the worst cruise line for environmental violations?
Carnival Corporation has faced the largest fines and most prosecutions for dumping violations across its brands (Carnival, Princess, Costa). Royal Caribbean also has a significant history of violations. Disney, Cunard, and some smaller lines have better records, though no cruise line has a perfect environmental history.