The victim was William Perrott, who mysteriously tried to swim ashore from his ketch Daisy as it lay anchored at the mouth of the River Blackwater sometime in 1933.
Records of the tragedy are scarce but indicate Mr Perry was a 33-year-old Welshman employed as a cabin boy.
Why he leapt from the ship will forever remain a mystery but William was quickly swept to his death.
His body was recovered about 6km upriver at Templemichael the next day.
His family travelled from Wales for his burial in Templemichael churchyard. His grave was marked by a simple wooden cross.
Youghal historian Mike Hackett said: “During their visit, William’s family arranged for a Tom Hickey of Templemichael to tend the grave and wrote to him every Christmas in appreciation.
“Eventually Tom passed away, the grave became shabby, and the cross decayed and fell.”
Following the funeral, William’s name had been carved, apparently by his brother, on a rock plateau by Youghal Lighthouse, within 500m from where he had leapt to his doom.
William Perrott’s story might have ended there had not a periwinkle picker accidentally re-discovered the inscription, hidden under seaweed, during the 1970’s.
A small seagull had also been carved alongside.
“Like a fairytale, small barnacles had grown into the depressions of the letters and it read white, as it still does, on the brown surface,” said Mr Hackett.
The historian is inviting the public to commemorate the seaman on Saturday.
“We will visit the rock, recite some prayers and say poems before proceeding to Templemichael graveyard, where William’s grave will be enhanced with a new timber cross, kindly donated by Colin Bulman of Egan’s Undertakers.”
Anyone interested is asked to assemble at the Walter Raleigh Hotel at 11am.