NAPLES, Fl. - The FBI is investigating the circumstances surrounding the disappearance of Tina White, 39, of Bonita Springs.

According to White's boyfriend, Andy Hopkins, the two left Fort Lauderdale last week for a week-long cruise to the Cayman Islands. But five hours into the trip, they got into an argument.

That's when Hopkins says he watched his girlfriend step onto the railing, and jump into the water. White's family has said from the beginning that they believe their daughter's disappearance is suspicious, saying she was afraid of heights and the water. But right now, there is no evidence suggesting foul play.

The US Coast Guard searched about 3,000 square miles of water for White's body before calling off the search a week ago.

The ship returned to Fort Lauderdale this past weekend and that's when the FBI went onboard to collect evidence from the couple's room.

The family says they just want closure. White's boyfriend says when the investigation has been completed, he'll be cleared.