The name of the boat, Mary, is a reference to the real-life ghost ship the Mary Celeste. It was an American merchant brigantine that was discovered adrift and completely abandoned in the Atlantic Ocean off the Azores Islands on December 4, 1872.
Emily Mortimer and Owen Teague accepted their roles in the film mainly out of a desire to work with Gary Oldman.
Anthony Jaswinski got the idea for the film watching families sail their boats across Florida oceans and lakes. He decided from the beginning that the film should take place on a haunted boat instead of a more extravagant cruise liner, compared to other ghost ship horror films.
At 53:23 as Sarah enters the closet you can clearly see the camera and camera man standing behind her