US Boating Law & Pollution Rules

Prerequisites

ASA 101 Keelboat Sailing 1, or the equivalent sailing experience.
Knowing the USCG required safety equipment for your boat.
A basic idea of what a holding tank and a marine head are.

Learning Objectives

This lesson covers the legal and environmental part of the ASA 103 Coastal Cruising standard. By the end of it you will be able to:

Explain the difference between state registration and federal documentation.
Say what boating education card you may need, and where to check.
State the federal blood alcohol limit for recreational boat operators and the penalties.
List the accidents a skipper must report, and the deadlines.
Name the placards and written plans a cruising boat must carry.
Explain the three types of marine sanitation device and what a No Discharge Zone means.

Who Makes the Rules

US boating law comes from two levels of government:

Federal law applies on all navigable waters. It is written in the US Code (Titles 14, 33 and 46) and detailed in the Code of Federal Regulations (CFR), mainly 33 CFR. The US Coast Guard enforces it.
State law adds rules on registration, education, speed, no-wake zones, and alcohol. States enforce on their own waters, often through a fish and wildlife or natural resources agency.

When the two differ, follow the stricter rule. A skipper who sails from state to state must check the local rules of each one.

Registration and Documentation

Most recreational boats are registered with the state where they are mainly used. The state issues a certificate and numbers that you display on the bow, plus a validation decal. Carry the certificate aboard.

Larger boats can instead have a Coast Guard Certificate of Documentation. This is a federal record of the vessel, issued by the USCG National Vessel Documentation Center. Federal law (46 U.S.C. 12102) ties documentation to vessels of at least 5 net tons. Net tonnage is a measure of internal volume, not weight; most sailboats over about 27 to 30 feet reach it.

Points to know:

For a recreational boat, documentation is usually optional. Owners choose it because it gives clear evidence of nationality when cruising abroad, and lenders often require it.
A documented boat shows its name and hailing port on the hull, and its official number permanently marked inside.
Some states still require a documented boat to carry a state decal. Check before you go.
On a charter boat, the documentation or registration papers should be aboard. Find them at the checkout.

Boating Education Cards

There is no federal boating licence for recreational skippers. Instead, most states require a boating education card for some or all operators, often based on date of birth. For example, Minnesota requires it for operators born on or after July 1, 2004, from July 2025.

Courses are approved against the National Boating Education Standards reviewed by NASBLA (the National Association of State Boating Law Administrators).
A NASBLA-approved card from one state is generally accepted for visiting boaters in other states, often for a limited period.
An ASA certificate shows sailing skill. It does not replace a state education card. Many charter companies ask for both.

Check the rules of the state where you will operate before you take the helm.

Boating Under the Influence (BUI)

Federal law treats drunk boating the same way as drunk driving.

Under 33 CFR 95.020, a recreational boat operator is under the influence with a blood alcohol concentration of 0.08% or more. For commercial vessels the limit is 0.04%.
An operator is also under the influence if impairment is apparent by observation, whatever the BAC.
The federal civil penalty is up to $5,000, and a criminal conviction is a class A misdemeanour (46 U.S.C. 2302).
State laws add their own penalties, which may include losing your driving licence.

Sun, wind, noise and boat motion make alcohol hit harder on the water. The skipper is responsible for the boat, so the safe rule is no alcohol for whoever is in charge.

Accident Reporting

Under 33 CFR 173.55, the operator must file a boating accident report when any of the following happens:

A person dies.
A person disappears from the boat in circumstances that suggest death or injury.
A person is injured and needs medical treatment beyond first aid.
Damage to boats and other property totals $2,000 or more, or any boat is a complete loss.

Deadlines:

Situation	Report within
Death within 24 hours, disappearance, or injury beyond first aid	48 hours
Other reportable accidents (death after 24 hours, damage)	10 days

The report goes to the state boating authority where the accident happened. If the operator cannot file, the owner must. This is separate from your duty to give help: the skipper of any boat involved must stop and assist others as far as it is safe.

Oil Pollution

Discharging oil or oily waste into US waters is illegal. That includes oily bilge water.

Under 33 CFR 155.450, every boat of 26 feet or more must display an oil discharge placard at least 5 by 8 inches, made of durable material, in the machinery space or at the bilge pump control station.
The placard warns that discharge is prohibited and that penalties apply.
If you see an oil sheen from your boat, stop pumping. Report spills to the National Response Center (1-800-424-8802).
Use absorbent pads in the bilge, and take oily waste ashore.

Garbage (MARPOL Annex V)

Federal law (33 CFR 151.67) bans throwing plastic or garbage mixed with plastic into the sea or any US navigable waters. It must be taken ashore or incinerated.

Boats of 26 feet or more must display a garbage placard that explains the discharge rules.
Oceangoing boats of 40 feet or more with a galley and berths (those that sail beyond 3 miles offshore) must carry a written waste management plan (33 CFR 151.57). The plan describes how garbage is collected, stored and disposed of, and names the person in charge of it.
In practice, the cruising rule is simple: bring everything back. Stow rubbish in bags, crush cans and bottles, and keep food scraps until you are ashore.

Sewage and Marine Sanitation Devices (MSDs)

Any boat with an installed toilet must have a Coast Guard-approved marine sanitation device (MSD). There are three types:

Type	What it does	Discharge
Type I	Macerates and disinfects	Treated effluent allowed, except in No Discharge Zones
Type II	Biological treatment and disinfection, to a higher standard	Treated effluent allowed, except in No Discharge Zones
Type III	A holding tank; no treatment	Pump out ashore, or discharge beyond 3 miles

Rules from the EPA:

Untreated sewage may not be discharged within 3 miles of shore. Inside that line, sewage must be treated by a Type I or II device, or held in a Type III tank.
Boats 65 feet and under may use Type I, II or III. Boats over 65 feet must use Type II or III.
In a No Discharge Zone (NDZ), no sewage at all may be discharged, treated or not. It must stay in the holding tank until you use a pump-out station. Many bays, lakes and harbours are NDZs.

Most cruising sailboats and charter boats have a holding tank with a Y-valve that sends waste either to the tank or overboard. Within 3 miles and in NDZs, the Y-valve or overboard seacock must be secured in the closed position: padlocked, wired closed, or with the handle removed. The Coast Guard checks this during boardings.

Coast Guard Boardings

The Coast Guard may stop and board any US vessel on US waters at any time to check documents and safety equipment. A boarding is routine, not an accusation.

Slow down or stop as instructed, and keep your hands visible.
Have your registration or documentation papers and ID ready.
Expect them to check life jackets, visual distress signals, sound signals, fire extinguishers, placards and your MSD.
A free Vessel Safety Check decal from the Coast Guard Auxiliary shows the boat passed an inspection recently. It does not exempt you from boarding.

Worked Example: A Weekend on a 34-Foot Charter Boat

You charter a 34-foot sloop for a weekend on a bay that is a No Discharge Zone.

At the checkout you find the state registration in the chart table. You check the oil and garbage placards are posted, since the boat is over 26 feet.
You check the head. The Y-valve is set to the holding tank, and the overboard seacock is closed with a cable tie. You leave it that way all weekend.
On Saturday afternoon the tank gauge reads three-quarters. You plan a stop at the marina pump-out station on Sunday morning.
A crew member offers a beer to the helmsman. You take the helm yourself until you are at anchor.
Coming into a slip, you touch another boat and leave a $1,500 scratch. No one is hurt. That is under the $2,000 threshold, so no federal accident report is needed, but you exchange details and tell the charter company at once.

Common Mistakes

Thinking an ASA certificate is a state boating licence. It is not.
Pumping out the holding tank "a little way offshore" while still inside 3 miles.
Leaving the Y-valve set to overboard after a passage outside the 3-mile line.
Pumping oily bilge water overboard because it "only looks like a little".
Throwing food scraps over the side in plastic bags.
Forgetting the 48-hour deadline when someone is hurt beyond first aid.

Summary

Most recreational boats are state-registered. Larger boats of 5 net tons and more may be federally documented.
Most states require a boating education card. Check the state where you operate.
The federal BUI limit for recreational operators is 0.08% BAC, or any observable impairment.
Report deaths, disappearances, injuries beyond first aid, damage of $2,000 or more, or loss of a vessel. Report within 48 hours for serious injury or death, otherwise 10 days.
Boats 26 feet and over need oil and garbage placards; oceangoing boats 40 feet and over need a written waste plan.
No untreated sewage within 3 miles, and no sewage at all in a No Discharge Zone. Secure the Y-valve.

Check Your Understanding

What is the federal BAC limit for a recreational boat operator? 0.08%, or any impairment apparent by observation.
A guest falls on deck and needs stitches at a hospital. Is a report needed, and by when? Yes. It is an injury needing treatment beyond first aid, so report within 48 hours.
Your boat is 28 feet long. Which placards must it display? An oil discharge placard and a garbage placard.
You are in a No Discharge Zone with a Type I MSD. May you discharge treated sewage? No. In an NDZ no sewage may be discharged, treated or not.
What should you do with the Y-valve when inside 3 miles of shore? Secure it so waste goes only to the holding tank: padlocked, wired, or with the handle removed.

Sources

https://www.law.cornell.edu/cfr/text/33/173.55
https://www.law.cornell.edu/cfr/text/33/95.020
https://www.law.cornell.edu/uscode/text/46/2302
https://www.law.cornell.edu/uscode/text/46/12102
https://www.law.cornell.edu/cfr/text/33/155.450
https://www.law.cornell.edu/cfr/text/33/151.57
https://www.law.cornell.edu/cfr/text/33/151.67
https://www.epa.gov/vessels-marinas-and-ports/vessel-sewage-frequently-asked-questions
https://www.nasbla.org/