Partners of the Tide (1921)

The Allen spinsters adopt Bradley Nickerson, who grows up with Gussie Baker, the little girl next door. Fifteen years later he is first mate of the Thomas Doane, owned by Granny Baker. A plot to sink the ship is averted by Bradley and a sailor, but ultimately the ship is sabotaged. The insurance company hires Bradley to investigate the wreck, but Sam Hammond, a deep sea diver, also in love with Gussie, is tampering with Bradley's diving gear at the moment a fire breaks out. Rowing to the burning ship, Bradley rescues Hammond, who then leaves him stranded, but Gussie rows out to save him, realizing at last the depth of her love.