DUI vs. BUI in Florida: What to Know

July 29, 2025 Don Pumphrey, Jr. Criminal Defense, Drunk Driving/DUI Social Share

In Florida, DUI (Fla. Stat. 316.193) and BUI (Fla. Stat. 327.35) are both very serious criminal offenses that can carry major penalties (including a felony conviction in some cases). However, there are key differences between DUI and BUI that are worth exploring.

This article will discuss the elements of both DUI (driving under the influence) and BUI (boating under the influence) in Florida, defenses to these charges, and potential penalties. It will also outline the differences between DUI and BUI.

DUI in Florida

For someone to be proven guilty of DUI, the State must prove all of the following beyond a reasonable doubt:

• The defendant was in operation of or had actual physical control of a motor vehicle within Florida, and
• The defendant was impaired by alcohol, a chemical substance, or a controlled substance (to the point where their physical/mental faculties were impacted), or
• The defendant had a blood alcohol concentration or breath alcohol concentration (BAC) of 0.08% or higher (grams of alcohol per 0.08 grams of alcohol per 100 milliliters of blood/210 liters of breath/67 milliliters of urine)

Actual physical control is defined as when a person is physically in or on the vehicle (such as sitting in the driver’s seat with the keys in the ignition) and has the capability to operate it, even if they are not actually driving. 

Before an officer can make a DUI arrest, they must develop probable cause that the person in actual physical control of the vehicle is impaired. This probable cause must be established by the totality of the circumstances, which may include officer observations of a driver’s behavior, their physical appearance, admissions made by the driver, or other relevant information State v. Kliphouse, 771 So.2d 16 (Fla 4th DCA 2000); State v. Saravia, — So.3d —- (2025).

Courts have held that an inebriated defendant standing along the driver’s side of the vehicle with his door open is not in actual physical control of the vehicle – if the officer does not otherwise observe them at another location that established actual physical control of the vehicle. State v. Bass, 19 Fla. L. Weekly Supp. 653a (Leon Cty. Ct. April 18, 2012). 

Florida law defines a vehicle as “every device in, upon, or by which any person or property is or may be transported or drawn upon a highway, except devices used exclusively upon stationary rails or tracks.”

This definition does not include trains or trams (operating only on rail or track), but does include:

• Cars, trucks, and SUVs
• Motorcycles
• Mopeds and motor scooters
• Golf carts or bicycles if operated on highways (Meister v. Fisher, 462 So. 2d 1071 (Fla. 1984))
• Commercial vehicles and RVs

For purposes of determining impairment, Florida’s courts have generally considered someone impaired for DUI purposes if their normal faculties are diminished. This may include their ability to see, hear, walk, talk, judge distances, drive, make judgments, or act in emergencies.  

Impairment is established in Florida if: 1) the defendant has a blood alcohol level/blood alcohol content (BAC) of 0.08 or higher, or 2) the State provides proof beyond a reasonable doubt of actual impairment due to intoxication. Tyner v. State, 805 So.2d 862 (Fla. 2d. DCA 2001)

Note: Since 2006, the only breath test machine approved for use as evidence in Florida is the Intoxilyzer 8000. Most DUI cases in Florida involve a breath test, but a urine or blood test might be requested under certain circumstances.

If someone is charged with (or convicted of) DUI, a common question is the penalties they may face. This largely depends on the number of prior DUIs and the level of impairment (BAC) that was detected under Fla. Stat. 316.193.

For a first DUI offense, this is typically a second-degree misdemeanor punishable by up to 6 months in jail. The defendant’s license must also be revoked for a minimum of 180 days if they are found guilty.

Other penalties may include:

• 50 hours of community service
• Up to 1 year of probation
• 12 hours of DUI school
• Up to 6 months of required use of an Ignition Interlock Device in vehicle

If someone has a blood alcohol content (BAC) of 0.15 or higher or has a minor in the vehicle, a first-DUI carries up to 9 months in jail (Fla. Stat. 316.193).

For a second DUI, someone faces more severe penalties. A second DUI is a first-degree misdemeanor punishable by up to 9 months in jail. Additional penalties may include:

• A fine of $1,000 to $2,000 (unless the driver blew a 0.15 or above or had a minor in the car, in which case the potential fine doubles to $2,000 to $4,000)
• 21 hours of DUI school 
• One year of required use of Ignition Interlock Device

If someone is charged with a third DUI, this may be a third-degree felony (punishable by up to 5 years) if the third conviction occurs within 10 years of a previous conviction.

However, if this is not the case, the following penalties may be imposed if someone is convicted:

• Up to 1 year in jail (first-degree misdemeanor)
• Minimum 180 days of license revocation
• Fines of $2,000 to $5,000 (at least $4,000 if BAC is >0.15 or minor in the car)
• 21 hours DUI school 
• Two years required use of Ignition Interlock Device

A fourth or subsequent DUI regardless of how many years have passed since the first is charged as a third-degree felony. Felony DUI penalties may include the following:

• Up to 5 years in prison
• Permanent revocation of driver’s license
• Up to $5,000 in fines

Note: DUI also requires impoundment of a defendant’s vehicle if convicted (taken to the police department). A first DUI conviction requires a minimum 10 days impoundment, a second DUI conviction (within 5 years) a minimum 30 days impoundment, and a third within 10 years requires a minimum 90 days impoundment.

If someone is arrested and charged with DUI in Florida, various defenses may be available, one or more of which may be applicable depending on the facts of the case. These include:

• Unlawful stop or arrest: For DUI, police must have reasonable suspicion to stop a vehicle (such as traffic violations or driving erratically). Without a justification for the stop, a defense attorney can move to dismiss the charges or suppress evidence on this basis.
• Miranda violations: Someone must knowingly, intelligently, and voluntarily waive their Miranda rights (right to remain silent, right to an attorney, etc.). If they were not notified of their rights or their waiver not valid, this can result in the suppression of a defendant’s post-arrest statements.
• Challenging BAC test results: Pursuant to Fla. Stat. 316.1932, breathalyzers must be properly calibrated and maintained. Moreover, certain medical conditions (such as acid reflux) may lead to artificially high BAC readings.
• Rising blood alcohol defense: As alcohol takes time to absorb, if someone consumed alcohol just before driving and did not have a BAC of >0.08 (or have impaired faculties) while in operation/actual physical control, this is potentially a viable defense.
• Challenging officer observations: If impairment was inferred based on subjective indicators (such as red eyes or slightly slurred speech) and the defendant did not have a BAC of >0.08, a defense attorney may argue this was the result of non-alcohol/drug causes (such as fatigue or allergies).
• Lack of actual physical control: If someone was not in actual physical control of the vehicle (e.g. sleeping in the backseat of a parked car while drunk with the keys on the floor), this disputes a central element of the charge.
• Medical necessity: Though rare, if someone suffered a life-threatening medical emergency while impaired and had no other choice but to drive to get help, this may be a viable defense.

Boating Under the Influence (BUI) in Florida

Like DUI, BUI (Fla. Stat. 327.35) is a very serious offense in Florida. For someone to be proven guilty of BUI (boating under the influence), the State must establish all of the following beyond a reasonable doubt:

• The defendant was operating, or had command or control of, a vessel in Florida
• The operator (or person in command or control of the vessel) had their normal faculties impaired by a substance (alcohol, controlled substance, etc.) at the time, or 
• Had a blood or breath alcohol concentration of 0.08% or higher 

For someone to be considered the operator of a vessel, they must do at least one of the following:

• Be in charge of the vessel (including the captain)
• Be actively in command of the vessel
• Be in actual physical control of the vessel while the vessel is moving (not anchored, moored or aground)

Note: Florida defines a vessel as “every description of watercraft, barge, and airboat, other than a seaplane on the water, used or capable of being used as a means of transportation on water.”

BUI has a similar sentencing scheme to DUI in Florida. Fla. Stat. Section 327.35 outlines the following penalties:

• First offense: Up to six months in jail and a $500 to $1,000 fine, potential suspension of boating privileges 
• Second offense: Up to 9 months in jail and fines of between $1,000 and $2,000, with a mandatory boating safety course and suspension of boating privileges
• Third offense: Up to 5 years in prison and a $5,000 fine if within 10 years – up to 1 year in jail and a $2,000 to $5,000 fine if not within 10 years of the last conviction
• Fourth or subsequent offense: Third-degree felony punishable by up to 5 years in prison, permanent license revocation

Defenses to BUI in Florida may include any of the following, one or more of which may be applicable in a given case:

• Challenging Breathalyzer test: This can include challenging the reading (for many reasons such as medical conditions, rising BAC, etc.) or arguing that the samples may have been contaminated depending on the chain of custody.
• Procedural defenses (Miranda violation allegations, motions to suppress evidence obtained in violation of a defendant’s rights)
• Field sobriety test challenges: BUI field sobriety tests are more subjective than DUI (less standardized) and may occur seated on a vessel. This can open up room for their results to be challenged.
• No actual operation: If the defendant was not in command of (captain) of the vessel at the time and was not physically operating the vessel, they have not committed BUI.
• No impairment: If BAC was not above 0.08 and the allegation of impairment was based on subjective officer observations, this can be aggressively challenged at trial.
• Rising blood alcohol content

The Differences Between DUI & BUI in Florida

Based on the above, it is clear there are key differences between DUI and BUI in Florida. Some of these differences include:

• Jurisdiction: DUI applies to vehicles on land whereas BUI applies to vessels on Florida’s waters 
• Stops: To stop a vehicle, law enforcement requires reasonable suspicion. However, FWC and Coast Guard can stop vessels for safety checks without observing a specific violation or signs of impairment
• Field sobriety tests: DUI field sobriety tests usually involve horizontal gaze nystagmus (HGN), walk-and-turn, and one leg stand. Conversely, BUI field sobriety tests have been adapted for vessels (seated tests like finger count, finger to nose, etc.). 
• Licensing: BUI does not result in a driver’s license suspension (though it may impact someone’s boating privileges if convicted)
• Actual physical control: Required for DUI, whereas the “operator” in the BUI context indicates that the captain/person in command of the vessel (such as directing movements or overseeing the boat) can also be found guilty of BUI even if not driving the vessel

Note: Under Trenton’s Law in Florida, it is a crime (as of October 1, 2025) for someone to refuse a DUI/BUI test (second-degree misdemeanor punishable by up to 60 days in jail and a $500 fine), even if it is the first time they have been stopped by police on suspicion of DUI or BUI. 

In sum, DUI and BUI are similar offenses that carry nearly identical criminal penalties. But there are key differences between them, including: jurisdictional distinctions (roads vs. waterways), whether reasonable suspicion is required for a stop, license suspensions, actual physical control requirements (depending on the context), and field sobriety tests used by police.

Defenses to both charges may include lack of actual impairment (if no BAC reading above 0.08), no operation of the vehicle/vessel (if not the captain of the latter), challenging field sobriety tests, rising alcohol levels, procedural challenges (suppressing evidence), and more. 

It is critical to find experienced and trusted legal representation as soon as possible if someone is charged with DUI, BUI, vehicular homicide, DUI manslaughter, BUI manslaughter or vessel homicide. This decision could make the difference in whether or not someone faces a lengthy prison term and hefty fines.

Criminal Defense Attorney in Tallahassee, FL

Don Pumphrey, Jr. is a Former Prosecutor, Former State Police Officer, Lifetime Member of the Florida Association of Criminal Defense Lawyers; for over 25 years as a private defense attorney who is Trusted, Experienced, Aggressive in Criminal Defense as a Trial Attorney, Criminal Lawyer, Criminal Defense Lawyer for the accused in Florida State Courts located in Tallahassee, Florida but handling cases throughout the State of Florida.

Don Pumphrey, Jr. and the Tallahassee criminal defense lawyers at Pumphrey Law have decades of experience fighting drug charges on behalf of clients and winning. Call Pumphrey Law now at (850) 681-7777 to learn more about what we can do for you. Our lawyers will be happy to provide you with a free consultation.

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