BEDFORD -- As Christopher and Carrie Monger navigated north on Smith Mountain Lake the night of Aug. 20, 2005, they noticed a larger boat cruising at a leisurely speed ahead of them. Its running lights were on, and it was moving just fast enough to slowly push ahead of them and out of sight.

Then Carrie Monger noticed a blip on the radar. She barely had time to warn her husband before a speedboat roared in behind them, coming within about 20 feet before it swerved to miss them.

About 10 minutes later, the Mongers came upon both the boats they had seen earlier. The speedboat had crashed into the back of the slower boat. As the Mongers aimed their spotlight at the cabin cruiser, they saw the body of Lawrence Lewis in the cockpit.

The speedboat's operator, Mark de Tournillon Sr., offered a tearful apology to the families of Lawrence and Judith Lewis as the battle over his sentencing drew to a close Tuesday in Bedford County Circuit Court. He told Judge James Updike he was ready to accept the consequences of the wreck that killed the Moneta couple and their dog.

"I am responsible," he said.

Updike seemed unmoved by the display of remorse. He glowered as he told de Tournillon, "It is the opinion of this court that operating that boat at that speed at night was criminally negligent even if you were completely sober." He sentenced de Tournillon, 46, to a total of 15 years in prison.

"There's nothing to rejoice over in a situation like this," said Bedford County Commonwealth's Attorney Randy Krantz. He called the sentence significant. The maximum possible punishment de Tournillon could have received was 21 years, while a proposal from the defense based on state sentencing guidelines for motor vehicle cases recommended a maximum of three years and nine months.

"The system didn't fail us," said Eric Spencer, Judy Lewis' son. He praised Krantz's efforts, but added, "Nothing's going to bring back Judy and Larry."

The wreck sparked community outrage at the lake and attempts to reform boating legislation during the past session of the state General Assembly.

With the sentence, loss and devastation continues for the de Tournillon family, said defense lawyer William Stanley. "I think he's paying for the sins of us all on the lake," he said.

Last week, de Tournillon settled two wrongful death lawsuits filed by the Lewises' estates for a total of $2.7 million. As part of the settlement, he must sell his business, Shoreline Marina.

De Tournillon had a reputation for being passionate about improving the lake. In the late 1990s the marina owner assisted with efforts to improve water quality, according to testimony Tuesday.

But de Tournillon also had a drinking problem that not only contributed to the wreck, but also provided fuel for prosecutors during Tuesday's long, hotly contested sentencing.

Police officers from Orangeburg, S.C., testified that in March, while he was out on bond in the deaths of the Lewises, they found de Tournillon slumped unconscious over the steering wheel of his car, which was parked in a stranger's yard.

The officer who tried to rouse de Tournillon noticed a holster in the passenger seat and found a loaded gun on the driver's side floorboards. De Tournillon resisted arrest, telling police any petty charges brought against him didn't matter because he was charged with killing a family and their dog in Virginia, according to testimony.

Ashley Harrison testified that in April her car was nearly struck in a Margate, Fla., parking lot by a truck that was pulling a trailer with a boat on it.

A man was passed out behind the wheel, and when police arrived they identified him as de Tournillon. Margate police testified that they found empty miniature vodka bottles in his truck. He was charged with operating a vehicle under the influence and refusing a blood test.

On June 9, after learning of the Florida charges, Updike revoked de Tournillon's bond in Bedford County. Three days later, de Tournillon pleaded guilty to operating a boat under the influence of alcohol and two counts of involuntary manslaughter while under the influence.

Defense attorney Al Prillaman said during closing arguments that he believed de Tournillon intended to use the gun he was found with in South Carolina to commit suicide.

"If I had the guts I would have pulled the trigger," de Tournillon said during his apology.

His attorneys said that he had been traumatized by the murder of his stepson in Broward County, Fla., in 1997.

Todd Dehli, a family physician and friend of de Tournillon, testified de Tournillon showed signs of post-traumatic stress disorder after the wreck. "I think he really wanted to talk to the Lewises. He felt terrible remorse," Dehli said, as de Tournillon began to sob.