Continuity mistake: When Tom Hanks is in the dinghy by himself, the outboard motor has no cover. He falls into the water and the dinghy circles him several times. One of the shots shows the motor with its cover in place. (It is an Evinrude motor).
Question: When Dr. Cornbluth first sees the mermaid under water and unsuccessfully tries to take her picture, how come he has an oxygen tank AND an air hose coming from the boat topside? I thought it may be a mistake but I am not a scuba diver so I though I would ask.