The One Fathom Bank Lighthouse (Malay: Rumah Api One Fathom Bank or Rumah Api Permatang Sedepa) refers to two offshore lighthouses in the Strait of Malacca, specifically, on a shoal within Malaysian waters, dubbed One Fathom Bank (Permatang Sedepa), off the coast of the state of Selangor. As neither lighthouse is located on any body of dry land, both locations are only accessible by boat. While both sites of the lighthouses are open, their towers remain off-limits.