While Thailand officials called off the search for Devine, the family still has a lot of questions about what happened to him.
"He's been In war zones since he was 18, and goes missing while on a diving trip. It just doesn`t equate," said Devine's sister Jennifer Bakowski.
Devine's family is offering a $5,000 reward for anyone with information that could lead to his whereabouts.
"We don't want to put anyone else in danger by coming forward, but we need to bring him home. We need closure to this," said Bakowski.
Devine, 36, a U.S. Army veteran who deployed to Kosovo and Iraq, owns land in Thailand with his wife, Thadsana, family members said. He is an experienced diver, and was traveling with her on a dive boat traveling from Phuket, an island province in the Andaman Sea.
Devin's sister Jenniger Bakowski says witnesses have told the family, Devine was drunk and somehow ended up going overboard, but his disappearance went unreported for hours.
"Nobody heard a splash. Nobody heard anything about him going into the water, he just "magically disappeared," Bakowski said.
The family released a document to Fox Connecticut Saturday that details email conversations between Devine's sister, the United States Embassy and an investigative reporter as the family digs for answers. His family has questioned whether foul play was involved.
Jennifer Bakowski and her mother went to Thailand in April to join the governor of Phuket and members of the Thai marine police in their search.
While in Thailand, Devine's family met with U.S. Embassy officials and an FBI agent.
They left without finding any clues to Devine's whereabouts, and the official search ended shortly thereafter.
The family hopes a $5,000 will help anyone come forward with information, past efforts have turned up no credible leads or information.
"We've been told that the Thai community is afraid to go forward. Because people go missing." said Bakowski.
Devine served two tours in the U.S. Army in Kosovo and Iraq and was a Sergent in the Connecticut National guard from 2002-2006. Devine worked as a I.T. specialist for a private military contractor at an army base in Kuwait.