One Fathom Bank Lighthouse, Maritime lighthouse off the coast in Selangor, Malaysia.

One Fathom Bank Lighthouse is a modern cylindrical steel tower with red and white stripes standing off the coast of Selangor, guiding vessels through the Strait of Malacca. The structure rises about 43 meters and emits regular light signals to help ships navigate safely through this busy waterway.

One Fathom Bank was first served by the lightship Torch, stationed on the shoal in 1852. A screw-pile lighthouse replaced it in 1874, and a concrete-pile lighthouse followed in 1907 at a cost of £246,963.31. That tower remained active until a larger lighthouse was built 500 metres away in 1999.

The bank's Malay name, Permatang Sedepa, is still used for the station, and the surrounding sea is a popular fishing ground. The 1999 tower's concrete jetty may be used by recreational anglers, and a traffic separation scheme runs west of the shoal. A Malaysian stamp issued on 31 January 2004 shows the old lighthouse.

The lighthouse sits about 23 nautical miles offshore and is best observed from the water. Visitors should know that this location is primarily relevant for maritime traffic and is not easily accessible from shore.

Two different structures actually stand on this sandbank: the restored original tower from 1907 and the modern tower from 1999. This is an unusual case in maritime infrastructure, where both buildings coexist side by side.