On 8 June 1912, the French Pluviôse-class submarine Vendémiaire made its inaugural dive during a military exercise off Cap de la Hague on the Normandy coast.
Shortly afterwards – somewhere near the Casquets reef off the coast of Alderney – it was accidentally sliced in two by the French warship St Louis and sank with the loss of all hands.
The vessel was deemed to be too difficult to recover and its exact final resting place has never been established.
But now a team led by French shipwreck expert Bertrand Sciboz is hoping to change that by diving for the wreck next year.
Through crowd-funding – the practice of financing a venture with money donated by a large number of people, usually via the internet – the group is hoping to raise more than 50,000 euros to fund the expedition.
‘We hope to be ready one year from now. We are prepping everything right now,’ said Mr Sciboz. ‘It is not the intention to bring anything to the surface. Finding exactly where the submarine is will be one of the toughest parts – it is in strong currents.
‘If we do not find it, we will try to raise more money to try again.’
It was hoped that finding the Vendémiaire would offer all of the families of those who lost loved ones some closure, he said.
Between five and ten days of good weather will be required, and experienced divers and a vessel equipped with sonar also have to be found.
Dives in the cold water would last 20 minutes each, with extremely strong tides posing another hazard.
Ten technical divers are being sought for the expedition, all of whom would have to complete a ‘check’ dive in similar conditions this summer.
The 51-metre submarine is thought to have gone down roughly on the border of French and Guernsey territorial waters. A documentary about the expedition will be made at the same time.
Seventy-five men died when the HMS Affray submarine went down 17 miles off Alderney’s coast on 16 April 1951 in the Royal Navy’s worst disaster since the Second World War.
In 2012 200 relatives and friends of those who died travelled to Alderney – with some coming from as far away as the Outer Hebrides – to attend the unveiling of a plaque dedicated to those who died.
Every one of the names of those who died was read out during the service, which was held on the Douglas Quay.
Alderney Museum also secured a piece of the submarine’s snort mast for a summer exhibition which coincided with the unveiling of the plaque.
The snort – an extendable tube used to ventilate a submarine while it is under water – is the only part of the craft to have been brought to the surface.
