The centenary of the sinking of the RMS Lusitania will be marked by a white rose, plaque and the names of the hundreds of souls who perished being placed on the wreck.
Gregg Bemis, the 87-year-old US entrepreneur who owns the liner 11 miles off the Irish coast, created his own heartfelt tribute rather than attend official commemorations.
The Cunard vessel was torpedoed by a German U-boat on May 7 1915 en route from New York to Liverpool and sank with the loss of 1,201 lives, including three unidentified stowaways.
The mementos will be placed on the boat 300 feet below the surface, off the Old Head of Kinsale, at 2.15pm on Thursday, the exact time the torpedo consigned the liner to its watery grave.
“It will be a permanent recognition of our feelings about the importance of the wreck – and to pay homage to the victims,” Mr Bemis said.
Diver Eoin McGarry, who has been on the wreck more than anyone, will descend to the frigid Atlantic seabed to leave the tribute.
“They say no flowers can be laid on a sailor’s grave but in this instance we are going to lay a flower on it,” he said.
The Lusitania sank 18 minutes after being struck – compared to two hours and 40 minutes for the Titanic – sparking theories over a second explosion caused by a secret cargo of high explosives destined for the British war effort.
The plaque, flower and list of names will rest near the ship’s bridge between two bollards.
There is also a theory that the captain ordered full steam ahead after the torpedo hit near the ship’s bow forcing water into the vessel at a dramatic rate.
On the eve of the anniversary the Irish government released state-of-the-art sonar imagery of the liner as it lies on its starboard side and stands 14m over the seabed.
Officials said the detail was key to protecting the site, adding: “One hundred years on, the Lusitania is beginning to reveal its wounds, scars and perhaps its secrets, and may continue to do so for many years to come.”
A minute’s silence will be held at a special service at Old Head overlooking the wreck site, while a plaque will also be unveiled and wreaths laid at the memorial.
The restored signal tower at the spot will also be officially opened.
Mr Bemis said he recognised the importance of the official anniversary engagements but said he planned the personal tribute as he relates more to the shipwreck.
Last year he sought permission from the Irish government to recover the double-faced bridge telegraph, visible on the wreck and potentially recording the last instruction from Captain William Thomas Turner to the engine room after the torpedo strike.
But he has been in dispute with officials over onerous conditions imposed on a licence for anyone to legally dive on the wreck.
“To my mind there’s been a huge cover-up of the actual cause of the fast sinking. I think that’s abysmal,” Mr Bemis said.
Mr Bemis has spent decades trying to confirm a theory that the 18-minute sinking was hastened by a second explosion caused by a secret cache of munitions destined for Britain’s war effort.
Mr Bemis said: “If there’s one thing I can do while I’m still here on earth I’d like to clarify that by getting the honesty and integrity of what happened out in the open, how it happened, why it happened.”
He has held meetings in the last week with lawyers as they assess options for a lawsuit against the Irish state over diving restrictions.
The businessman from New Mexico invested in the wreck for salvage in the 1960s and now claims diving on it could leave him open to claims from descendants of the dead for the desecration of graves.