Jones said Shepherd would not be eligible for work release or reduced time for good behavior, and the man was immediately taken into custody.
After Shepherd's boat struck University of Utah lab specialist Esther Fujimoto, 49, as she was swimming on the evening of Aug. 21, 2011, the men allegedly motored away without attempting to help the fatally wounded woman.
In December, Shepherd was found guilty by a jury of misdemeanor charges of reckless endangerment, obstructing justice and failure to render aid.
Two of Shepherd's friends, Colton Raines, 23, and Robert Cole Boyer, 30, also are charged with obstructing justice. And Raines, who was driving the boat when Fujimoto was hit, is charged with reckless endangerment and failure to render aid.
Before he was sentenced, Shepherd turned to face Fujimoto's family and read an apology from a letter.
"I wish I could have gone back and been more cautious, and more careful," he read, adding that he was ready to take responsibility for his actions.
But the victim's brother, Bryan Fujimoto, said outside of court that he didn't find the apology believable.
"One word comes to mind: disingenuous," he said. "I don't feel he was remorseful. It was disingenuous and self-serving."
Jones also felt that Shepherd showed little to no emotion or remorse during a preliminary hearing and trial, which he said was troubling.
"It's troubling for me as a judge to hear this case not once, but twice, and every time I looked at you, I saw no remorse," Jones said. "Nothing."
Shepherd's attorney, Glen Neeley, asked the judge for probation and work release if Shepherd was sentenced to jail, saying his client had never been in trouble with the law before and had good character. He also pointed out that Shepherd was the only one of the three men who spoke with police about the incident.
"Without Skyler, I don't think they'd have much of the truth," Neeley told the judge.
A trial for Raines and Boyer is set for February. Shepherd was given a subpoena in court on Wednesday, and will be expected to testify about the fatal collision.
Deputy Weber County Attorney Dean Saunders said Shepherd doesn't have a legal right to refuse to testify. If he chooses not to, he will face contempt of court charges.
Saunders said his office has told Raines and Boyer's attorneys that they are open to negotiating a plea deal, but as of Wednesday, he said he had not seen any paperwork suggesting what the other two men would agree to plead guilty to.
According to testimony during Shepherd's trial, the men were boating near the Spring Creek Cove area of the reservoir at about 8 p.m. after drinking with friends earlier. Witnesses who were with the men that day testified that Raines and Boyer also had smoked marijuana. While Raines was driving the boat at the time of the accident, Shepherd took the wheel when they circled back to check on Fujimoto. He told police that Fujimoto said she was OK, so they left.
But Chief Medical Examiner Todd Grey testified that the injuries to Fujimoto's lower abdomen and legs from the boat's rotor meant she likely would have been in severe pain. She died soon after a lakeshore resident who heard her screams rowed out to rescue her.
At the time the trio was charged, leaving the scene of a boating accident involving serious injury or death was only a misdemeanor. Fujimoto's case spurred Utah lawmakers to pass a bill last year elevating such behavior to a third-degree felony, punishable by up to five years in prison.