MAYPORT NAVAL STATION, Fla. - A group of male submarine sailors traded illicit videos of female officers in various stages of undress as if they were Pokemon cards, a 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," said a Navy prosecuting attorney, Lt. Cmdr. Lee Marsh. 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 crew change has not been without incident, overall it has been a success.