LONDON (Reuters) - Divers have recovered two World War Two-era “bouncing bombs” from the bottom of a Scottish loch after a seven-year hunt aided by the British navy.

The spherical Highball devices, developed by British war-time “Dambuster” engineer Barnes Wallis, are similar to the bombs used to destroy German dams during the war.

They did not contain explosives and were used as a prototype for tests, the British Sub-Aqua Club, which led search, said in a statement.

Divers from the club, assisted by a navy ship and crane, hauled the bombs from Loch Striven, west of Glasgow, on Wednesday and Thursday. They now intend to offer them to aviation museums.

“It was unbelievable to see the first one come out of the water,” project leader Mark Paisey said.

“It was covered in mud and marine crustaceans but when we cleaned it off it was perfectly preserved, down to the nuts and bolts. No-one has seen one of these for the best part of 75 years, so it was quite emotional to see it close up.”

The Highball bombs were intended for use against Germany’s Tirpitz battleship, but were never deployed due to the positioning of the vessel in a Norwegian fjord.

They were then moved to the Pacific for use against Japanese ships, but the war ended before they could be used.