This is a prosthetic Shelley Winters, constructed by makeup effects supremo Maurice Seiderman (CITIZEN KANE, BRIDE OF THE MONSTER) for NIGHT OF THE HUNTER. The kind of thing you really don’t expect to see in a ’50s movie, and it’s so convincing you don’t realise you are seeing it. Easier to believe Shelley has an oxygen tank hidden just out of sight. I think it’s often evidence of a good film, when the crew find themselves doing unconventional things, or finding new ways to solve old problems.
Shelley never had much luck in the water, did she? Asides from the hauntingly evoked watery grave above, she suffered an aquatic heart attack in THE POSEIDON ADVENTURE and drowned in A PLACE IN THE SUN. I assume something bad happens to her in TENTACLES, and even in LOLITA, where her character’s death by drowning was altered by Kubrick so he wouldn’t have to film on an unconvincing studio lake, James Mason responds to her passing by taking a bath.
Seiderman is a fascinating figure. He was employed by RKO to sweep the floor in the hair and makeup department, when Welles spotted his talent and allowed him to design the old-age makeup for KANE. Seiderman invented the soft contact lens as part of his work. Later he designed Welles’ prosthetics for TOUCH OF EVIL, but his IMDb credits look painfully incomplete: even some of the films listed, he received no credit for.