Lansdowne Bank
One of the world's largest submerged banks, in the Coral Sea.
Lansdowne Bank, also recorded as Landsdowne Bank, is a vast submerged bank in the eastern Coral Sea, lying between New Caledonia’s main island and the Chesterfield Islands. Spanning 4,300 km² (1,660 sq mi), it ranks among the world’s largest banks. Its depths generally range from 60 to 80 metres (197–262 ft), and the seafloor is mostly sandy. Two reefs mark the shallowest points, but both remain underwater even at low tide.
In the same area, some maps show a submarine feature called Fairway Ridge (or Fairway Plateau). The Lansdowne Bank area is considerably larger than Fairway Plateau, though several smaller, unnamed plateaus exist nearby. The bank sits at the northeastern end of the Lord Howe Rise and is separated from New Caledonia by the northern New Caledonia Trough.
**Nereus Reef** lies at the bank’s northern end, though its recorded position (20°07′S 160°28′E) is uncertain. It is the shallowest point on the bank, with a least depth of 3.7 metres (12 ft). About 14 miles (23 km) west-northwest of Nereus Reef, a shoal reaches a depth of 16 metres (52 ft).
**Fairway Reef** marks the southeastern end of Lansdowne Bank. It gets its name from its location in the fairway between Australia and New Caledonia, halfway between the Bellona Reefs (south of the Chesterfield Islands) and New Caledonia. The reef is 3.2 kilometres (2.0 mi) long, with depths of about 4 to 5 fathoms (7.3 to 9.1 metres) and a coral bottom. Its coordinates are 21°00′15″S 161°45′09″E. Some sources report that Fairway Reef dries at low tide.
**Sandy Island Mystery**: Google Maps and other online maps once showed a large landmass called Sandy Island in the northern part of Lansdowne Bank, but no image was provided. French missions in the 1970s had already proven the island did not exist, and this information was shared with hydrographic services worldwide. Despite this, the phantom island remained in the World Vector Shoreline Database. In 2012, Australian scientists confirmed once again that the island is not there.
- Area
- 4,300 km² (1,660 sq mi)
- General depth
- 60 to 80 metres (197–262 ft)
- Least depth
- 3.7 metres (12 ft) at Nereus Reef
- Location
- between New Caledonia and the Chesterfield Islands, eastern Coral Sea
- Bottom type
- largely sandy
- Shallowest features
- two reefs, submerged at low tide
Lore & Background
Lansdowne Bank is situated at the northeastern end of Lord Howe Rise, separated from New Caledonia by the northern New Caledonia Trough. Two reefs mark the shallowest spots of the bank, but they remain submerged at low tide. Nereus Reef, at the northern end, has the least depth of the bank at 3.7 metres (12 ft), though its given position of 20°07′S 160°28′E is doubtful. A shoal with a depth of 16 metres (52 ft) lies 14 miles (23 km) west-northwest of Nereus Reef.
The southeastern end of the bank is marked by Fairway Reef, named for its location in the fairway between Australia and New Caledonia, midway between the Bellona Reefs and New Caledonia. Fairway Reef is 3.2 kilometres (2.0 mi) long, about 4 to 5 fathoms (7.3 to 9.1 metres) deep, of coral bottom, and located at 21°00′15″S 161°45′09″E. According to some sources, Fairway Reef dries at low tide.
A notable feature of Lansdowne Bank is the Sandy Island mystery. Google Maps and other internet maps showed a large landmass named Sandy Island in northern Lansdowne Bank, but did not show an image for it. The non-existence of this phantom island had been proved by French missions in the 1970s, and the information passed to hydrographic services around the world, but it remained in the World Vector Shoreline Database. In 2012 Australian scientists again proved the island does not exist.
Reader's Guide
Lansdowne Bank's significance lies in its scale and its role as a navigational landmark in the Coral Sea. As one of the largest banks in the world, covering 4,300 km², it presents a vast submerged area with general depths of 60 to 80 metres. Its shallowest points are marked by two reefs—Nereus Reef and Fairway Reef—which, though submerged at low tide, pose hazards to shipping. Fairway Reef is particularly notable for its position in the fairway between Australia and New Caledonia, midway between the Bellona Reefs and New Caledonia, giving it a direct navigational importance. The bank's legacy also includes the persistent cartographic error of Sandy Island, a phantom landmass that appeared on internet maps and in the World Vector Shoreline Database despite being proven nonexistent by French missions in the 1970s and again by Australian scientists in 2012. This error highlights the challenges of mapping remote oceanic features and the persistence of outdated data. The bank's location at the northeastern end of Lord Howe Rise, separated from New Caledonia by the northern New Caledonia Trough, further situates it within a complex submarine geography that includes the nearby Fairway Ridge and smaller unnamed plateaus.
Did You Know?
- Lansdowne Bank covers an area of 4,300 km², making it one of the largest banks in the world.
- The bank's shallowest point is Nereus Reef, with a depth of 3.7 metres (12 ft), though its position is considered doubtful.
- Fairway Reef, at the southeastern end, is named for lying in the fairway between Australia and New Caledonia.
- A phantom island called Sandy Island appeared on maps in northern Lansdowne Bank but was proven nonexistent by French missions in the 1970s and again in 2012.
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