The WWII device was found at 5:00am on the morning of Wednesday 16th November 2016 by a barge dredging the harbour ahead of HMS Queen Elizabeth’s arrival next spring.
The bomb was towed out to open waters 1.5 miles east of the Isle of Wight, where a controlled explosion took place at 4:00pm on the same day.
Harbour movements were restricted while the device was towed out through the harbour entrance.
Captain of Portsmouth Naval Base, Captain Bill Oliphant, said: “This is the third piece of historic ordnance found in the harbour during the dredging works since September.
“We worked closely with Hampshire Police and Portsmouth City Council to ensure we dealt with this incident in the safest way possible, at the same time causing least disruption to the city.”
Commander Del McKnight, in charge of the bomb disposal team involved in the operation, said: “Everything went smoothly and we were pleased to be able to get the operation completed in daylight today. Despite being old, these devices still pose a very serious threat when they are moved.”