Top brass at Plymouth's naval dockyard have called in ghost-busting experts - to see if the base is haunted.
Sailors have seen ghosts in old dockyard buildings
A team of paranormal investigators will arrive at Devonport Dockyard on Friday armed with night-vision cameras, dowsing rods and sound equipment.
The research will focus on the Hangman's Cell where naval ratings have been spooked by a strange "atmosphere".
The team will also examine sightings of a Victorian girl's ghost seen playing in the Master Ropemaker's House.
The 20 researchers include psychics, mediums and paranormal scientists from Brunel University, the Society of Metaphysicians and the Cornwall-based Paranormal Research Organisation.
They will split into two teams and spend two nights monitoring the "goings-on" at the dockyard which have left several naval ratings "spooked and scared".
Devonport Dockyard is the largest naval base in western Europe. It was founded in the 17th Century by William of Orange.
It has the only working gallows in the country and it is thought more than 100 men were executed in the dockyard.
Ian Addicoat, president of the Paranormal Research Organisation, says it is a unique opportunity as the Royal Navy would not normally give permission.
The Royal Navy has agreed to let the experts into the yard in the hope of finally putting an end to years of rumours about its ghosts.
Mr Addicoat said: "We should be in for an interesting couple of days.
"If there are ghosts or strange occurrences, we stand a great chance of finding out.
"We will be using scientific equipment and bringing our best investigators."
He added that the team will not have any preconceived views, but has high hopes with the dockyard's history.
Every movement, sound and temperature change will be recorded and analysed before the team presents its findings to the Royal Navy.
A naval base spokeswoman said: "This is part of research for the naval base visitor centre, in particular the Master Ropemaker's House and the Hangman's cell.
"We hope to back up the information we give to visitors about the history of the building with scientific and other research.
"There have been a number of first hand reports of ghostly happenings and sightings over the years and it is hoped this research will either prove or disprove that the paranormal is at work in the naval base."