The mystery of how a 250lb American wartime bomb ended up on the Falmouth shore may never be solved, but the Commanding Officer of the team that removed it has put forward a couple of "plausible" scenarios.
Earlier this evening, Lt Cdr Ben Brown, Commanding Officer of Bravo Squadron, described the device as "unusual" and revealed that his team must wait "a further six days" until it can be detonated after it was moved to an area at sea suitable for disposal.
When asked to elaborate, he explained: "The unusual nature was the fact that it was American. The majority of bombs that we deal with – such as the bombs in Plymouth – are German. Historically it's German ordnance that we mainly deal with, but we do deal with Allied ordnance a lot, but usually smaller – grenades, mortars.
"We don't deal with [American] ordnance as often. The scientists in the background at DSTL [Defence Science and Technology Laboratory] have links with different nations and they would speak with their German equivalent colleagues for information because the prevalence of Allied ordnance over there is far more than over here.
"Then the second thing was the type of fusing that goes into this type of bomb."
He said that they were unable to confirm the exact fuse type but it could be a long delay chemical fuse, with that delay being "anywhere between an hour and 144 hours" – or six days.
He continued: "Whenever you interact with a bit of ordnance – you move it or you do a positive EOD action, like some disruptive action, you need to wait a certain period after that before you know it's safe to go in. And with this particular type of fuse you don't know if you've restarted it – and because you can't look at it and tell the amount of time left on the timer you have to wait the maximum amount of time that has been set for."
Lt Cdr Brown said that once the bomb was set down where it currently rests it has to be left the appropriate time before his team can safely return and attach a small charge to it.
He said: "Hopefully, in the next six days, nothing will happen, we can come back to it next week and we will then conduct a small controlled explosion and get rid of it safely."
He agreed it was "exactly" like the old safety measure of not going back to a lit firework that appears to have gone out, until you are absolutely sure it's safe to do so.
He added: "The reason for all that is you have to make it as safe as possible. Everyone – the police, the council – are working really hard to keep the public safe. My job is to make sure my guys are safe as well.
"I need them to do more of these jobs, so they need to be around.
"It's not lost on us the level of disruption that comes with these types of task. We're very well briefed on the level of impact it causes the local community, but ultimately we just have to be as safe as we can."
As for how the bomb ended up in our waters, Lt Cdr Brown accepted that any explanation was just speculation, but he said there were a few plausible ones available.
He explained: "It's probably been in that location [in the water just off the shore] until the point it was discovered.
"It's 113kg – no-one's going to have been shifting that around. We have seen instances in the past where fishermen have dredged them up. I've personally dealt with one off Essex where a fisherman dredged it up in his net. It gets moved when they drop their nets.
Recap the full drama over two days in our live blog here.
"In this case I would say it's just been there for a long time. We get occasions when you have a storm or a significant tidal surge or springs, that can uncover stuff. There's a whole host of reasons why it may not have been discovered until now.
"As for why it's there, we couldn't tell for certain, but there are a couple of scenarios spring to mind.
"Allied bombers going out on patrols in the western approaches, anti-submarine warfare or a training mission with live weapons to do practice bombing runs and the aircraft has had some sort of issue and it's had to return to the airfield they came from."
Falmouth Bomb to Wait Six Days Before Detonation