The 500 pound World War Two device was picked up during dredging work.
Dorset Streets Remain Safe At Night
Dorset Police say crime hasn't increased at night despite worries over turning some street lights off.
In some parts of the county, street lights are now switched off between 1am and 6.30am (midnight to 05:30am in winter).
Concerns were raised by some members of the public that this would lead to an increase in crime but that hasn't happened.
Police tell us monitoring carried out to date has shown no link between lights being switched off and changes in crime and disorder levels.
Deputy Chief Constable, James Vaughan, said:
"We take the concerns of our communities very seriously and have worked together with our local authority partners in Dorset County Council to closely monitor the areas where street lights have been switched off in case of any changes in crime levels.
"I'm pleased to say that we have found there has been no link to an increase in crime, which I hope will offer some reassurance to residents.
"We do understand that people can feel less safe when street lights are off and we will continue to work together with partners to monitor crime levels. Dorset County Council has agreed to reconsider street lighting in cases where crime is seen to increase or where there are local crime and disorder issues that need particular focus."
Latest figures show that crime in Dorset is at a 15-year low - with total crime down 11 per cent on last year.
Hilary Cox, Dorset County Council's Cabinet member for Environment, said:
"We welcome the evidence from the police about our part-night lighting programme. It is reassuring that the scheme, which does make savings, has not caused an increase in crime. The scheme has been strongly supported by those who want to reduce the amount of light pollution in our night skies."
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.
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