BOSTON -- The search continued Tuesday for a missing sailor who was last seen outside the Black Rose Pub in Boston on Friday night.

NewsCenter 5's Jack Harper reported that Petty Officer Dustin Willis, 26, was out with friends on Friday night before becoming separated from the group. Willis called his North Carolina home at about 10 p.m.

"We are still deeply concerned, as you can imagine, as each day and each hour passes for his safe return to the ship. That is our biggest concern right now -- his safe return to the ship," said Navy Lt. Paul Brawley.

Willis' ship, the USS Donald Cook, a destroyer, is set to leave Boston on Wednesday.

"He got a Navy achievement award for superior performance last week. So, this is totally out of character. He is a guy who is on time, dependable and reliable -- a good petty officer," Brawley said.

When Willis walked out of the bar with his friends Friday night, they lost sight of him.

"When his friends came around the corner, they didn't see Mr. Willis. They assumed that he might have gone into one of the nightclubs. They began looking into the nightclubs to see if they could see him. They didn't see him. One of his crewmembers called his cell phone, left a message that they were heading back to the ship and to contact the ship," Boston Police Department Detective Sgt. Kevin Finn said.

Officials said that Willis' cell phone was found at about 1 a.m. on Long Warf, but detectives are not sure if Willis was there.

"There was no indication of any altercations between him and the individuals he was out with or any individuals he may have encountered on the street," Finn said.