BUI Attorney in Walnut Creek

Defending Boating Under the Influence Charges in Contra Costa County

Boating under the influence is a criminal charge under California Harbors and Navigation Code Section 655, a statute separate from the Vehicle Code DUI law that governs motor vehicles. That distinction matters: BUI carries its own procedural rules, its own courts, and consequences many boaters don’t anticipate until after an arrest on the Sacramento-San Joaquin Delta or another Contra Costa County waterway. Thomas Daly defends BUI charges for clients throughout Contra Costa County, including at the Martinez courthouse where these cases are prosecuted.

The Contra Costa County Sheriff’s Marine Services Unit patrols more than 80 square miles of waterways, from Richmond to Discovery Bay, with certified Marine Enforcement Officers on the water seven days a week. Summer months bring concentrated enforcement activity, and many boaters are caught off guard by consequences that parallel a land DUI, including potential jail time, fines, and a permanent criminal record.

A BUI arrest requires prompt attention. Contact Thomas Daly Law, A Professional Corporation at (925) 208-4801 for a free consultation and a candid assessment of your case.

What California Law Prohibits Under HNC 655

Harbors and Navigation Code Section 655(b) makes it unlawful to operate any vessel while under the influence of alcohol, drugs, or both. The statute sets BAC thresholds based on the type of operator: 0.08% for recreational boaters under Section 655(c) and 0.04% for commercial vessel operators under Section 655(d). The law covers motorized boats, sailboats under power, jet skis, and personal watercraft, tracking the language of Vehicle Code 23152 but substituting “vessel” for “vehicle.”

One distinction worth noting: unlike the open container rules that apply to motor vehicles, alcohol isn’t prohibited on a boat itself. The law targets operating a vessel while impaired or above the BAC threshold. Still, several nuances catch boaters off guard:

• Below 0.08% isn’t automatically safe. Even below that threshold, a charge is possible if an officer determines the operator’s ability to safely control the vessel is impaired.
• Boaters under 21 face zero tolerance. Under Harbors and Navigation Code Section 655.6, a BAC of 0.01% or more is an infraction, and reaching 0.05% or above can support misdemeanor charges under the general BUI statute.
• Anchored vessels can still support a charge. Retaining operational control of a vessel while anchored may be sufficient in certain circumstances.

BUI Penalties Under California Law

A first-offense BUI is a misdemeanor carrying up to six months in county jail and fines up to $1,000. Probation is typically available, but a conviction creates a permanent criminal record. A second or subsequent BUI within seven years carries up to one year in county jail. That seven-year lookback includes prior DUI convictions under Vehicle Code 23152 or 23153, vehicular manslaughter, and BUI manslaughter.

One consequence that surprises many people: under Vehicle Code Section 23620, a BUI conviction counts as a prior offense in any future DUI prosecution. A first BUI followed by a DUI within the lookback period can be treated as a second offense with escalated penalties. The relationship runs in the other direction as well, with prior DUIs counting toward a BUI lookback.

BUI causing injury under HNC 655(f) is a wobbler, meaning the prosecutor may charge it as a misdemeanor or a felony carrying 16 months to three years in state prison, depending on the severity of injury and the defendant’s record. Unlike a standard DUI, a BUI conviction doesn’t automatically trigger a California driver’s license suspension, though DMV action remains possible for commercial drivers, repeat offenders, and injury cases.

Other collateral consequences of a BUI conviction include:

• Mandatory education program. Completion of an alcohol or drug education program of up to 18 months, depending on BAC level and prior history.
• Criminal record. Permanent record affecting employment and professional licensing.
• Insurance and vessel consequences. Increased rates and possible vessel impoundment or forfeiture.
• Immigration exposure. Potential consequences for non-citizen defendants.
• Enhanced sentence for test refusal. Willfully refusing a chemical test after a lawful officer request under HNC 655.5 gives the court discretion to impose an enhanced sentence upon conviction.

Defense Strategies for Contra Costa County BUI Cases

The marine environment creates defense opportunities that don’t exist in standard DUI cases. Thomas Daly examines each BUI case for weaknesses in the prosecution’s evidence, from the circumstances of the initial stop or boarding through the administration of field sobriety tests and the handling of breath or blood samples. His familiarity with Contra Costa County court procedures at the Martinez courthouse informs how he evaluates local law enforcement’s BUI investigations and how he approaches negotiation with local prosecutors.

Several defense considerations apply specifically to BUI cases:

• Legality of the stop. Law enforcement must have probable cause or reasonable suspicion before stopping or boarding a vessel. A stop lacking legal justification can result in suppression of evidence obtained during the encounter.
• Field sobriety test reliability. Tests administered on a moving or rocking vessel are inherently less reliable than those on stable ground. Vessel motion, engine vibration, and wave action naturally affect balance and coordination.
• Environmental impairment factors. Sun exposure, heat, dehydration, and wind can produce physical symptoms that mimic alcohol impairment, including red eyes, unsteady footing, and slurred speech. These conditions are cross-examinable as alternative explanations for an officer’s observations.
• Chemical test integrity. BAC results can be challenged on grounds of improper calibration, faulty equipment, chain-of-custody failures in blood sample handling, or the timing of the test relative to when the vessel was operated.
• Pretrial diversion. For first-time misdemeanor BUI charges, pretrial diversion may be available. Successful completion may result in dismissal of the charge and help avoid a conviction on the defendant’s record.
• Charge reduction. Negotiation for a reduction to a reckless boating charge is a potential outcome that carries significantly less severe consequences than a BUI conviction.

One-on-One BUI Defense for Contra Costa County Clients

Thomas Daly represents clients facing criminal charges throughout Contra Costa County, including the full range of DUI-related offenses. BUI fits within that established practice as a distinct but related charge governed by its own code section and carrying its own procedural posture. What he brings to each BUI case is what he brings to every client: direct, personalized representation in which the specific facts, circumstances, and goals of that case drive the defense strategy. His courtroom experience at the Martinez courthouse provides practical familiarity with local procedures and prosecutors.

Schedule a Free BUI Consultation Today

Evidence in a BUI case is time-sensitive. Witness recollections fade, equipment calibration records have retention limits, and the window for certain defense motions is governed by procedural deadlines. Acting quickly after an arrest can give Thomas Daly the opportunity to evaluate the full picture of the case.

Thomas Daly Law, A Professional Corporation offers free consultations for individuals facing BUI charges in Walnut Creek and throughout Contra Costa County. Reach out by phone at (925) 208-4801 or through the online contact form to schedule a conversation about your case.