A typical episode follows the crew of a particular vessel as it prepares to embark upon a voyage and concludes at the end of the journey or once a particular job has been completed. The operational capabilities and technical aspects of the ship feature heavily in the series, whilst members of the ship’s crew provide an insight into life at sea and provide a human perspective. The series also makes use of computer-generated animation to show scenes which would otherwise be unobtainable, such as underwater operations.

The series was started after the success of a one-off special on the Discovery Channel entitled Inside Queen Mary 2. The series has featured an extensive range of different types of marine vessels, with cruise ships, an aircraft carrier, fishing boats, dredgers and various types of cargo ships, naval and specialist ships being shown.

The show's mixture of technical insight and human stories has proved popular with audiences.