| Prong’s Lighthouse Colaba Point | |
| Location: | Mumbai, India |
| Coordinates: | 18.8792°N 72.7998°W |
| Yearbuilt: | 1844 (first) |
| Yearlit: | 1871 (current) |
| Construction: | stone tower |
| Shape: | tapered cylindrical tower with double balcony and lantern |
| Marking: | black basement, white tower with a horizontal red band, white lantern |
| Height: | 41m (135feet) |
| Focalheight: | 41m (135feet) |
| Lens: | 1st order Fresnel lens |
| Range: | [1] |
| Characteristic: | Fl W 10s. |
| Managingagent: | Mumbai Port Trust[2] |
Prong's Lighthouse is an offshore lighthouse situated at the southernmost point of Bombay (present-day Mumbai), India in the Colaba (Navy Nagar) area. It marks the entrance to Mumbai Harbour. The lighthouse is a Grade-I heritage structure.
During the 18th century, with an increase in the number of shipwrecks in the Bombay harbour region, a need for a lighthouse was met by modifying an onshore watch tower, built by the Portuguese, into the first lighthouse by British port authorities. This was known as the Colaba Point Lighthouse.[3] The Prong's Lighthouse was built later, in 1875, by Thomas Ormiston at the cost of Rs. 620,255.[4] The lighthouse had a cannon during the British rule, to secure the bay. Once the Prong's Lighthouse was completed and commissioned, the older Colaba Point Lighthouse was rendered obsolete and it was demolished and no trace of it remains today.[5] [6]
The tapering 44m (144feet) high circular stone tower has a 23m (75feet) range and a beam that can be seen at a distance of 30km (20miles). The tower is painted in three horizontal bands, red, white, and black respectively.[7] It displays a white light, flashing every ten seconds.[8]
The Prong's Lighthouse is one of the few offshore lighthouses in the world that are still staffed. It is maintained by the Directorate General of Lighthouses and Lightships, that comes under the Ministry of Ports, Shipping and Waterways. The lighthouse has restricted access as it is in a military area. It is accessible during low tide by foot and during high tide by boat, with special permission from the Indian Navy and the Mumbai Port Trust.[9]
The lighthouse is one of the three lighthouses in the Mumbai Harbour. The other two lighthouses include the Dolphin Lighthouse and the Sunk Rock Lighthouse.
The lighthouse (and the mangrove area extended between it and Colaba point) was designated a Grade-I heritage structure by the Brihanmumbai Municipal Corporation (MCGM) basis the recommendations of the Mumbai Heritage Conservation Committee.[10]