In ten days’ work, Devonport-based survey ship HMS Echo found a string of sunken obstacles and wrecks – including what is believed to be a sunken amphibious ship from the Gaddafi era – in the waters of the capital Tripoli and the port of Al Khums.

Lying some 160 feet (ft) beneath the surface of the Mediterranean, the Gaddafi era ship was one of nearly 20 wrecks and objects peppering the seabed off Libya, found by HMS Echo in a remarkable 10-day search for hidden dangers to mariners.

Three-dimensional image showing the wreck of a merchant ship [Picture: Crown copyright]

HMS Echo was the first Royal Navy vessel into Libya after the 2011 civil war and downfall of Colonel Gaddafi.

She returned this year for a concerted period of survey work – work which reaped rewards in and around Tripoli earlier this month with various obstacles found in and just outside the harbour.

Further sweeps using the advanced sonar of both HMS Echo and her survey boat, Sapphire, over a 10-day period located 1 liner, 2 merchantmen, 1 warship, 2 fishing vessels, at least half a dozen shipping containers, 2 barges (one of them wooden) and 4 very large sunken pontoons.

HMS Echo's survey boat, MB Sapphire, alongside the wreck of the Al Ghardabia in Tripoli Harbour [Picture: Crown copyright]

Around 6 miles off the coast of the port of Al Khums (also known as Khoms), Echo’s scanners picked up the distinctive shape of a warship.

Lieutenant Jen Smith was Echo’s Officer of the Watch when the wreck was discovered:

It’s always exciting when we locate something on the seabed that no-one knows about,” she said. A lot of merchant shipping waits at anchor in this area if there are no spaces in the port. Now we know about this wreck, we can warn them all to stay clear and avoid any danger.

Multibeam echo sounder image of a wreck in the port of Al Khums [Picture: Crown copyright]

The wreck is 298ft (91 metres [m]) long and has a shallow draft – about 7-10ft (2-3m). Given the dimensions and outline, it could be a Soviet-built Polnocny-class landing ship which could discharge armour on to a beach. Colonel Gaddafi had 4 such ships, but one, the Ibn Qis, burned out in a training exercise in 1978.

HMS Echo also moved further out to sea searching for the wrecks of the Italian liners Neptunia and Oceania which were pressed into service to ferry German and Italian troops to North Africa in 1941.

Wreck in Tripoli Harbour [Picture: Crown copyright]

Both were torpedoed and sunk within minutes of each other some 60 miles off Tripoli by Victoria Cross winner Lieutenant Commander David Wanklyn and his submarine HMS Upholder.

Echo searched 15 square miles of seabed looking for the 590ft liners at their reported last positions, but to no avail.

Otherwise, Echo’s Commanding Officer, Commander Matt Syrett, is delighted by the results of his team’s survey efforts.

Multibeam echo sounder image of a wreck [Picture: Crown copyright]

The data his ship has collected will be used to update charts of the area – and more accurate charts mean shipping companies can bring larger vessels into ports and cut insurance costs.

Commander Syrett said:

The data we have gathered will mean that merchant vessels can enter Libyan waters with confidence.

HMS Echo is in the early stages of an 18-month mission to improve seafarers’ charts on behalf of the UK Hydrographic Office in Taunton, who produce the world-famous, and heavily used, Admiralty Charts.