Henderson Island, South Pacific (Picture: Royal Navy).
Henderson Island in the South Pacific (Picture: Royal Navy).

Navy radars prove Oxford-sized island is in 'wrong place'

Henderson Island, South Pacific (Picture: Royal Navy).
Henderson Island in the South Pacific (Picture: Royal Navy).

Sailors from HMS Spey have shifted a remote Pacific island one mile south on the world's maps – after proving it's been in the wrong place for 85 years.

Henderson Island in the South Pacific is an uninhabited land mass roughly the size of Oxford, one of four islands in the Pitcairn chain sitting between Chile and New Zealand.

The Royal Navy's offshore patrol vessel corrected charts used by mariners since 1937 while checking the waters around British Overseas Territories using sonar, satellites and airborne laser techniques.

The service collects data on areas and seas to inform its digital charts and navigate safely.

Previous satellite data had proven some inconsistencies with historical charts, prompting HMS Spey to get involved.

Navigator Lieutenant Michael Royle used the ship's sensors and GPS positioning to gather a radar image, before comparing it to existing maps.

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"In theory, the image returned by the radar should sit exactly over the charted feature – in this case, Henderson Island," he explained.

"I found that wasn't the case – the radar overlay was a mile away from the island, which means that the island was plotted in the incorrect position when the chart was first produced."

He added: "The notes on the chart say that it was produced in 1937 from aerial photography, which implies that the aircraft which took the photos was slightly off in its navigational calculations."

Henderson Island was last visited by the Navy in 2018 – HMS Montrose conducted a survey to study the environmental impact of plastics in the oceans.

The Pitcairn grouping lies 3,600 miles west of Chile and 3,200 miles northeast of New Zealand.