The 500 pound World War Two device was picked up during dredging work.
Bug-Hit Oriana Returns To Southampton
A luxury cruise liner described as a "plague ship" after an outbreak of the winter vomiting bug has returned to dock in Southampton.
Around 300 passengers on P&O's Oriana are thought to have been struck down with norovirus during a 10-night Baltic cruise.
The company's owners, Carnival, initially said there had been "an incidence of a mild gastrointestinal illness" among the 1,800 people on board.
Paul Gilman, who had booked onto the cruise, said: "It has been outrageous from start to finish.
"People were falling like flies, yet the crew were trying to insist everything was fine.
"Everyone is saying, 'this is a plague ship'. It's a living nightmare."
Carol Marlow, managing director of P&O Cruises, said the Oriana had undergone a "full sanitisation process" before it set sail from Southampton on December 4.
She said the first cases of norovirus, which has an incubation period of between one and two days, were reported to the ship's medical centre within a couple of hours of the vessel leaving port, indicating the virus was brought on board by one of the passengers.
Ms Marlow, who sent a letter of apology to all customers, said: "We don't want one person to be ill on any of our holidays, and we'll learn from this and try to make sure it doesn't happen again."
More than 750,000 people could be affected by the latest outbreak of norovirus in the UK, according to estimates by the Health Protection Agency.
The stomach bug is highly contagious and causes vomiting and diarrhoea.
640 men were killed when the South African troop carrier was hit by a cargo ship in 1917.
The 79-year-old man suffered a serious head injury in the Cranmer Road car park in Winton.
Two Girls Indecently Assaulted Last Sunday
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