Innerspace-Dennis Quaid, Martin Short, Meg Ryan, Kevin McCarthy-1987 IMDb 6.8/10

A scientifically miniaturized marine unexpectedly finds himself floating around the body of a hypochondriac and trying to outwit saboteurs who want the device that shrank him. Attempts by his colleagues to retrieve him, who is protected inside a tiny submersible, are hampered by the would-be thieves.