A disgraced merchant marine officer elects to stay aboard his sinking cargo ship in order to prove the vessel was deliberately scuttled and, as a result, vindicate his good name.

Matt Braddock is a civil engineer during World War II who has new ideas for shipbuilding. Braddock tries to establish yards for building prefabricated ships on the West Coast, but he is hindered by the former superintendent of the shipyard, Joel Kennedy. A disappointed lover fails to deliver an important message on welds and it leads to the collapse of a new ship's superstructure and the death of a boy.