Four thousand poppies were laid at the Scottish Parliament in memory of each of the victims of Britain's worst maritime disaster.
The Clyde-built liner the Lancastria came under attack and sank near France during the Second World War.
An estimated 4,000 people died - more than the combined death toll from the Titanic and Lusitania tragedies.
Survivors and relatives of victims are calling for official recognition for those caught up in the disaster.
They gathered at the Scottish Parliament on Sunday to launch a petition asking MSPs to commission a Lancastria medal in their honour.
Survivor Reg Brown said: "It is only right that we finally get the recognition we deserve.
"I lost many good friends aboard the Lancastria and when I and the other survivors returned to the UK we were told not to mention it.
"Winston Churchill was worried about the impact such a loss would have on public morale.
"That may have been acceptable at the time but since then there has been no formal recognition of the sacrifice made, or the numerous acts of selflessness and courage which were shown by the survivors as they struggled and helped each other in the sea."
Survivor Bill Hughes was a crewman the day Lancastria sank
The Lancastria was lending support to the war effort when it was attacked by German bombers on 17 June, 1940.
The ship had been evacuating British Expeditionary Forces from France. About 400 Scots were among the 4,000 who died.
MSP Christine Grahame, who supports the campaign for greater recognition for those on board the Lancastria, attended the poppy laying event.
Ms Grahame said: "Although 67 years have elapsed since the disaster, the pain of relatives and victims remains very real.
"It is compounded by the fact that no official formal recognition has ever been offered to those who were aboard Lancastria that day. I hope my colleagues are able to remedy that."