The Twilight Zone

The Thirty-Fathom Grave

Season 4, Ep 2, Aired 1/10/63
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  • Episode Description
  • A US naval destroyer investigates a mysterious tapping sound coming from a sunken submarine.

  • Cast & Crew
  • Rod Serling


  • Perry Lafferty

  • Herbert Hirschman

  • George T. Clemens

  • Ralph W. Nelson

  • Fan Reviews (3)
  • Poor again

    By noman, Aug 22, 2014

  • A US Navy destroyer spots something on sonar while out at sea. That something turns out to be a Navy submarine sunk by the Japanese during World War II. Also, a strange tapping sound seems to be coming from the wreck.

    By meathead704, Jul 28, 2008

  • about a person that was suppose to die 20 years ago in a submarine. then they go back to the same spot and the ship is still there.

    By tz4569, Feb 23, 2008

  • Trivia & Quotes
  • Quotes (2)

    • Closing Narration
      Narrator: "Small naval engagement, the month of April, 1963. Not to be found in any historical annals. Look for this one file under 'H' for haunting--in the Twilight Zone."

    • Opening Narration
      Narrator: "Incident one hundred miles off the coast of Guadalacanal. Time: the present. The United States naval destroyer on what has been a most uneventful cruise. In a moment, they're going to send a man down thirty fathoms to check on a noise maker--someone or something tapping on metal. You may or may not read the results in a naval report, because Captain Beecham and his crew have just set a course that will lead this ship and everyone on it into the Twilight Zone."

    Notes (2)

    • Included on volume 20 of Image-Entertainment's DVD collection.

    • This episode, as with all in Season 4, were an hour in running time. All episodes in Season 1-3 & 5 were only 30 minutes.

    Trivia (4)

    • The young seaman McClure turns out to be a qualified diver, and is therefore given orders to investigate the sunken submarine up close. Therefore he is often seen "uncovered," i.e. not wearing hat or uniform. Yet in one scene, he gives uncovered salutes to Captain Beecham upon arrival and dismissal... a violation of protocol in the Navy, Coast Guard, or Marines. Only the Army and Air Force observe both covered and uncovered salutations.

    • The hull number of the sunken submarine is revealed to be 714, and we are told that it was built during the war in 1941. Any American sub built from 1941 through 1943 would have had a hull number in the 200s... the number 714 wasn't reached for another 36 years (1979, the USS Norfolk).

    • In the long shots they show the U.S.S. Mullinnix (DD944) not the U.S.S. Edson (DD946) which is on the jackets and is were the show was filmed.
      –former USS Edson crew member
      *fyi: The ship is available to be visted at

    • When Beecham is telling Bell that the sinking of the sub wasn't his fault, you can see on the shots of his face that his hair is combed back, off of his forehead. But on the shots of him from behind you can clearly some hair hanging down.

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