Divers have raised the gun from a First World War German submarine which has lain on the seabed for more than 80 years.

Maritime history experts are excited by the discovery of the 16ft U-boat deck gun, which is a rare find.

It will go to the Newhaven Local and Maritime Museum at Garden Paradise, Avis Way, Newhaven, where visitors will be able to watch it being restored.

Members of the Tunbridge Wells British Sub Aqua Club donated the gun after raising it six miles off Newhaven on Friday.

Club member Roger Theobald said he had explored the sub many times before and knew the gun was there.

He decided to bring it to the surface when he realised it was about to fall off and disappear into the sandy seabed forever.

Following months of planning, it took 20 divers in four boats just 40 minutes to raise the deck gun, which weighs more than a tonne, by attaching airbags to it.

Mr Theobald said: "It sounds easy but it was quite complicated. The wreck has been salvaged before by a scrap metal firm but, for whatever reason, nobody ever bothered about the gun.

"The staff and volunteers at the museum are over the moon."

Museum volunteer Russell Whiteside, who is overseeing the restoration project, said there were only a handful of such U-boats in service during the First World War.

He said: "The Allied governments disarmed the German fleet after confiscating the submarines, which is why this gun is very rare.

"This U-boat was about to be scrapped and was being towed back to Britain. Mysteriously it sank en route. Maybe they thought it wasn't worth taking it all the way back.

"What is remarkable is that the piece is in immaculate condition considering it has been on the seabed for 82 years."

The gun could be on show at the museum by next week.