Carrying a gun on a boat is legal in many circumstances, but the rules change with the water beneath you. State law controls most inland lakes, rivers, and nearshore coastal waters. Federal rules layer on once you enter navigable waters or a federally managed lake. And the moment you cross into another country’s territorial sea, your American permits stop mattering. A firearm that’s perfectly legal at your dock can become a serious offense a few miles away.
State Waters: The Default Rules
On inland lakes, rivers, and coastal waters inside state boundaries, state firearm law is the primary authority. The open-carry and concealed-carry rules that apply to you on land generally apply on your boat.
Twenty-nine states allow some form of permitless carry, so residents (and often visitors) can carry a handgun without a state-issued permit. In the remaining states, having a loaded firearm on a watercraft without a valid concealed carry permit is typically illegal.
How the state classifies your boat can also matter for self-defense. A houseboat used as a primary residence has a stronger claim to “dwelling” status, which can bring Castle Doctrine protections into play. Some states define their protected spaces broadly enough to include vessels. Idaho defines “habitation” as any building or conveyance designed to be occupied by people lodging overnight, and North Carolina defines “home” as any conveyance designed as a temporary or permanent residence. A small fishing boat used for an afternoon on the lake is far less likely to qualify.
Who Cannot Have a Firearm on a Boat at All
Federal law bars certain people from possessing firearms anywhere, boat included. The prohibited categories cover anyone convicted of a crime punishable by more than one year in prison, anyone subject to a domestic violence restraining order, anyone convicted of a misdemeanor crime of domestic violence, fugitives, people addicted to controlled substances, and those dishonorably discharged from the military, among others.1Office of the Law Revision Counsel. 18 U.S. Code 922 – Unlawful Acts No state permit overrides a federal disqualification.
Navigable Waters and the Coast Guard
When your boat is on “navigable waters of the United States” — the territorial sea, the Great Lakes, interstate rivers, and other waterways used in interstate commerce — federal jurisdiction can layer on top of state law.
No federal regulation specifically bans firearms on private recreational vessels. The Coast Guard does not require you to hold a permit or lock up your guns simply because you’re on navigable water. What the Coast Guard does have is broad authority to board. Under 14 U.S.C. § 522, commissioned and petty officers may board any vessel subject to U.S. jurisdiction, inspect documents, search the vessel, and use all necessary force to compel compliance.2Office of the Law Revision Counsel. 14 USC 522 – Law Enforcement You cannot refuse a Coast Guard boarding the way you might decline a warrantless search on land.
The boarding team will ask whether you have weapons aboard, and if you do, an officer will typically secure them for the duration of the inspection.3USCG Boating Safety Division. A Boater’s Guide to the Federal Requirements for Recreational Boats Boarding officers are armed. Declaring firearms honestly is both legally smart and practically safer.
One thing to keep in mind: the boundary between state and federal waters is not marked with buoys. You can drift from a state-controlled bay into a federally regulated channel without noticing, and the legal framework governing your firearm can shift with your position.
Army Corps Lakes: The Trap Most Boaters Don’t Know About
Some of the most popular boating lakes in the country are managed by the U.S. Army Corps of Engineers, and the firearm rules there catch people off guard. Federal regulation prohibits possessing loaded firearms, ammunition, bows, crossbows, and other weapons on Corps-managed projects as a default rule. Your state concealed carry permit does not override this. Neither does a permitless-carry state law.
The exceptions are narrow: law enforcement officers, hunters and anglers participating in programs run through the local lake office, users of authorized shooting ranges, and anyone with written permission from the District Commander.4eCFR. 36 CFR 327.13 – Explosives, Firearms, Other Weapons and Fireworks If you’re planning a trip and want to bring a firearm, check who manages the lake before you launch.
National Park Waters
National Park units work differently. Since 2010, you can possess a firearm in any National Park System unit as long as you’re not otherwise prohibited and you comply with the firearm laws of the state where the park sits. But carrying a loaded weapon in a vessel propelled by machinery is prohibited. The only exception is a non-motorized vessel being used as a shooting platform in accordance with federal and state law.5eCFR. 36 CFR 2.4 – Weapons, Traps and Nets Motoring across a lake inside a national park means your firearm needs to be unloaded and cased.
Crossing State Lines by Water
Boaters traveling between states often rely on the Firearm Owners’ Protection Act, specifically the safe-passage provision in 18 U.S.C. § 926A. The law lets a gun owner transport firearms through states where possession might otherwise be illegal, provided the trip begins and ends in places where you can legally possess the firearm.6Office of the Law Revision Counsel. 18 USC 926A – Interstate Transportation of Firearms
The storage rules during transport are specific. The firearm must be unloaded, and neither the firearm nor any ammunition can be readily accessible from the passenger area. If there’s no compartment separate from the passenger area, the firearm and ammunition must be in a locked container other than a glove compartment or console. The statute does not require ammunition to be stored separately from the firearm; it just requires that both be inaccessible.
The catch is that FOPA was drafted with cars in mind. It talks about a “transporting vehicle” and a “passenger compartment,” language that maps neatly onto a sedan with a trunk and awkwardly onto a center console. Whether the safe-passage protection extends to boats at all is legally unsettled. Most boats have no compartment truly separate from where passengers sit, which means the locked-container requirement almost certainly applies if the law covers boats at all. A locking hard case stored below deck is the safest approach.
Even where FOPA clearly applies, it has limits. Extended stops or side trips can strip away the protection. And some local authorities in restrictive jurisdictions have arrested travelers and forced them to raise FOPA as a defense in court. Being legally right and being free to go are not the same thing.
Marinas, Cruise Ships, and Flare Guns
Privately owned marinas can set their own firearm policies as private property. Many prohibit the display or use of firearms and require guns to be unloaded and locked while docked. Breaking these rules is not usually a criminal matter, but it can end your moorage agreement.
Commercial vessels like cruise ships and passenger ferries almost universally ban firearms on board, regardless of your permit status. Attempting to bring a gun onto a cruise ship can result in denied boarding and criminal charges, especially when the ship docks in a foreign port.
Flare guns, which many boaters carry as required safety equipment, are a common source of confusion. Under federal law, a device originally designed as a weapon but redesigned for signaling or pyrotechnic purposes is explicitly excluded from the definition of “destructive device.”7Office of the Law Revision Counsel. 26 U.S. Code 5845 – Definitions A standard marine flare gun used for its intended purpose sits outside federal firearm regulation. Some states and Canada treat them differently, though, and loading a flare gun with an antipersonnel round converts it back into a weapon under most legal frameworks.
Foreign Waters
Entering another country’s territorial waters with a firearm aboard is where the stakes climb sharply. Most nations are far less permissive than the United States, and American permits carry no weight abroad. Declare all firearms and ammunition to foreign customs immediately on arrival. Failing to declare is treated as smuggling in most jurisdictions.
The Bahamas
Only shotguns and handguns are allowed in Bahamian waters. You must declare any firearm to Bahamian Customs and provide the serial number, manufacturer name, and an exact ammunition count.8U.S. Embassy Nassau. Boating in The Bahamas Weapons must remain under lock and key on the vessel at all times; you cannot take them ashore without a special license. Firearms staying in Bahamian waters for more than three months also require a special license.9Bahamas Laws. Firearms (Forms and Fees) Rules
Canada
Canada requires visitors to complete a Non-Resident Firearms Declaration form before arriving at the border. A customs officer must witness your signature, and the declaration costs $25. Once signed by the officer, the form serves as a temporary license valid for 60 days.10Royal Canadian Mounted Police. Non-residents Some firearms cannot enter Canada at all. Prohibited firearms include automatic and converted automatic weapons, and center-fire semi-automatic firearms other than handguns originally designed with a detachable magazine of six or more rounds that were manufactured on or after December 15, 2023.11RCMP. Information Sheet: Non-Resident Firearm Declaration – RCMP GRC 5589e Bringing a prohibited firearm can result in seizure and forfeiture.
Mexico
Mexico is where American boaters get into the most serious trouble. Mexican law provides penalties of 5 to 30 years in prison for bringing a firearm or even a single round of ammunition into the country without prior authorization. A limited exemption for first-time, unintentional violations involving a single non-military weapon may reduce the punishment to a fine, but it is not something to rely on. Before heading for Mexican waters, strip the boat of every firearm, every round, and every spent casing. U.S. citizens have ended up in Mexican prisons over ammunition they forgot was rolling around in a storage compartment.
Before any international trip, research the destination country’s firearm importation laws in detail and contact its embassy or consulate if anything is unclear. Penalties abroad run from heavy fines to years of imprisonment and forfeiture of your vessel, and the legal process in a foreign country is rarely quick or familiar.