A group of male submarine sailors traded illicit videos of female officers in various stages of undress as if they were Pokemon cards, a U.S. Navy prosecutor said Thursday.

Navy prosecutors presented evidence against two of 12 male sailors accused of illegally making and trading videos of female officers aboard a nuclear submarine that was among the first to allow American women to serve alongside men.

The two men in court Thursday, both missile technicians aboard the USS Wyoming nuclear submarine, were accused of trading the videos with other sailors.

Another sailor aboard the Wyoming made the videos with his smartphone and then told others that he had a "gift for them," Navy prosecuting attorney Lt. Cmdr. Lee Marsh said. The Wyoming is based at Kings Bay Naval Submarine Base in Georgia.

Marsh said that once the sailor who took the videos arrived back onshore, he shared them with the others by "bumping" their smartphones together. The videos were not posted online.

"Videos were treated like Pokemon (cards). Something to be collected," Marsh said during the preliminary hearing in the case against two missile technicians charged with conspiracy to distribute recordings of private areas of female officers.

Navy Vice Adm. Michael Connor, commander of the nation's submarine fleet, has characterized the case as a "serious sexual offense, with significant penalties."

The case highlights issues the Navy has faced in switching to coed crews on ballistic-missile submarines. It began the practice in 2011.

More than 50 women now serve aboard submarines, and Connor has said while the change to coed crews has not been without incident, overall it has been a success.

Navy Lt. Paul Hochmuth, defense attorney for one of the accused missile technicians who was in court on Thursday, said his client didn't know what the files were when he accepted the "gift" on his phone.

He argued that the government was unfairly describing the videos as graphic -- he said they were of poor quality, were only ever viewed on smartphones and showed only partial nudity.

"At no point can you ever see a full length view of the person. ... You might see a face ... then a leg ... or a butt ... but there is no full length view," Hochmuth said.

Marsh said the quality of the videos is irrelevant because they were made without consent and that they were plenty graphic.

"The videos consist of ... undressing for the shower and drying off from the shower," he said.

The hearing was presided over by a Naval officer, who listened to statements from both sides and will issue a recommendation to Rear Adm. Charles Richard, commander of submarine group 10.

Richard will decide whether to pursue courts-martial trials against the defendants, dismiss the charges or use other administrative methods to deal with the cases.