Officials said Ryan Hayward, 25, of Rockland hasn't been heard from since September 11.
His family stated that's highly unusual and they're also concerned because he has a serious medical condition.
Police added Hayward is a local long shore fisherman and the last information they had on his location placed him in the Boston area..
His family has decided to turn to the public for help because they've done as much as they can on their own and none of his friends have heard from him.
Anyone with information that could help is asked to contact the Knox County Sheriff's Department.