Most people know you can get a DUI in a car, but far fewer realize you can be arrested for operating a boat while impaired. I am Joel Brand, and I defend DUI cases across California. Boating under the influence, often called a BUI, is a real offense with real consequences, and it comes with its own set of rules that differ in important ways from a roadside DUI. If you were cited or arrested on the water, here is what you need to understand.
Boating under the influence is its own offense
California law makes it illegal to operate a vessel while under the influence of alcohol or drugs, a subject I cover in depth in boating under the influence in California. It is a distinct offense from a vehicle DUI, with its own statute, but it shares the core idea, you cannot operate a vessel when your ability to do so safely is impaired. The 0.08 alcohol threshold that applies to drivers also applies to boat operators.
It applies to more than just motorboats
The reach of the law surprises people. It can apply not only to powerboats but also to personal watercraft like jet skis, and in some circumstances to other vessels and water activities. Many people assume a small recreational craft does not count, the same way they assume a golf cart or a bicycle does not, and they are surprised to learn the law extends to operating these on the water while impaired.
Who can stop you on the water
On the water, a wider range of agencies can be involved than on the road. Harbor patrols, county sheriff marine units, state wildlife officers, and the Coast Guard may all have authority on the water. This means the rules around stops can be different from a roadside traffic stop, and understanding which agency was involved, and what authority they had, is part of evaluating a BUI case.
Safety stops are common on the water
Boating is subject to safety and equipment checks in a way driving generally is not. Officers can stop vessels for safety inspections, checking life jackets, registration, and equipment, and a BUI investigation sometimes begins from one of these encounters. How the contact started, and whether it was a proper basis for the investigation that followed, can be a meaningful issue in the case.
Field sobriety tests on the water are different
The standard field sobriety tests were designed for solid ground, not a rocking boat or a dock. Officers may use modified tests suited to a marine environment, but balance and coordination are affected by the motion of the water, sun, wind, fatigue, and the physical experience of being on a boat all day. Someone who has been boating for hours is at a built-in disadvantage on these tests that has nothing to do with alcohol, and that is worth raising in the defense.
The all-day sun-and-water factor
A day on the water combines several things that can affect both your condition and the testing. Sun exposure, dehydration, the constant motion, and hours of physical activity can all leave a person looking impaired in ways that mimic intoxication. These environmental and physical factors are part of the human reality of boating, and they can provide innocent explanations for the signs an officer attributes to alcohol.
The rising blood alcohol issue
Just as with a car DUI, the timing of your drinking matters. If your last drink came shortly before you were stopped, your blood alcohol may still have been rising, meaning a later test could read higher than your level when you were actually operating the vessel. This rising blood alcohol argument, which I explain in the rising BAC defense, applies on the water just as it does on the road.
The consequences are serious
A BUI is not a minor citation. A conviction can carry fines, possible jail, and other consequences, and in serious cases, especially those involving injury, the stakes climb significantly. People sometimes assume a boating offense will be treated casually, and they are surprised by how seriously it can be prosecuted. That is precisely why a BUI deserves a real defense rather than a quick resolution.
Memorial Day and the start of boating season
BUI arrests cluster around the warm-weather boating season, which kicks off around Memorial Day, as I noted in my post on a Memorial Day weekend DUI. Holiday weekends on the water bring heavier enforcement, with marine patrols out in force. The same patterns that produce summer roadway arrests, long days of drinking and heavy enforcement, play out on the water too.
The defenses still apply
A BUI is defended on many of the same principles as a vehicle DUI. The basis for the stop, the reliability of any chemical test, the timing of your blood alcohol, and the validity of the field sobriety evidence in a marine setting can all be challenged. Many of the approaches in my guide to the top DUI defenses apply, adapted to the realities of the water. A BUI is far from an automatic conviction.
What it can mean for your driver's license
People are often surprised to learn that a boating offense can have implications beyond the water. While a BUI arises under boating law rather than the vehicle code, a conviction can still affect you in ways that reach your record and, depending on the circumstances, your standing as a driver. Understanding exactly how a BUI interacts with the rest of your record is part of evaluating the real stakes, and it is one more reason not to assume a boating charge is a minor matter that will simply go away on its own.
The bottom line
Boating under the influence is a real and seriously prosecuted offense in California that applies to boats, personal watercraft, and more, with its own rules about who can stop you and how the testing works, but it is also defensible, with the marine environment itself often providing innocent explanations. If you were arrested on the water, get a free written case analysis below, or call me directly at (888) 271-6644. I answer my own phone, 24/7. You can also read more from the DUI blog.