The second one was identified as a 250lb anti-submarine bomb and for the second time in two days a Royal Navy team carried out a controlled explosion.
The blast was heard across Town at about 9.20 yesterday morning and a small crowd of onlookers on the Castle Emplacement saw plumes of water lift towards the sky.
All eyes had been on a red buoy just outside the harbour mouth and the crowd were alerted when the fuse was lit.
RN Petty Officer diver Gavin Speer said it all went smoothly.
‘We came out on Monday to do a recce on an unexploded bomb. We confirmed it on Tuesday and we placed a charge on it and successfully detonated that, and then later we got a phone call from the harbour master saying that another one had been found, so we did another dive to recce it.
‘It was exactly the same as the previous day – an anti-submarine dropped weapon. It contained about 70 kilograms of TNT so my dive team placed another charge on it and successfully detonated that as well.’
A 500-metre exclusion zone had been set up around the device and after the explosion the harbour became a hive of activity with fishing boats, yachts and the Travel Trident allowed to get on their way.
The Portsmouth-based Royal Navy team was operating within their own Covid-19 bubble, maintaining social distance and wearing masks, after being given critical -worker status.
Mr Speer said finding two bombs in two days was quite a surprise.
‘It is unusual, but I suppose where there’s one there’s often more, and luckily the team was on the island so we were able to quickly come down this morning.’
Granted permission to spend five minutes diving below the first bomb’s marker buoy to film the crater, divers JP Fallaize and Mat Le Maitre were dropped by skipper Richard Keen and travelled down the heavy sinker block chain.
At around 5.20pm Mr Fallaize saw what looked like a bomb, about 10ft away from where the other one was, which raised suspicion.
‘I noticed a lot of concretion casting had fractured that was covered with seaweed,’ he said.
‘I knocked away all the concretion and it was a nice shiny-looking bomb.’
Having been diving for 24 years, Mr Fallaize has been present at explosive identification and disposal procedures around six or seven times.
‘It was difficult to see, but you do get an eye for it – the same as scallops. After a while if there’s anything interesting you see it.’
Mr Le Maitre had swum over the four-foot long, 10-inch wide AS250 anti-submarine bomb.
‘Mat swum back towards me, and we’re at the end of our bottom time. Back at the top I said to Richard, “I don’t know if this is going to cause any hassle?’’, and he called it in.’
By 6.30pm discussions were under way with the navy’s bomb disposal unit and local harbour authorities, socially-distanced with face masks.
‘I was very impressed with how swift they were getting plans in place.’
Footage from the dive should be posted on Mr Fallaize’s YouTube channel soon. Visit youtube.com/user/guernafroman/videos to watch.