Forty descendants took part in a wreath-laying service over the wreck site yesterday.
Divers from the Royal Navy’s Northern Diving Unit took a single wreath to the seabed to place on the wreck.
They had earlier recovered a White Ensign, laid on the wreckage of the Vanguard in 2009, and replaced it with a new flag.
Among the victims was Lieutenant Evelyn Dunbar-Dunbar-Rivers, known to his family as Evie, who joined the Vanguard in November 1913.
He was 26 on the night the ship went down and his portrait hangs in the hallway of the family home.
His great-nephew Duncan Dunbar-Nasmith, of Glen of Rothes, Moray, was among the descendants at the ceremony.
He said: “I’ve grown up with the painting. To be in Scapa Flow, on the waters above the ship, our links with him feel so much more substantial – we feel closer to a man whose life came to a sudden end at such a young age so long ago.
“It has been wonderful for us to be among so many descendants of those who served aboard Vanguard. None of us will forget the sacrifice they made.”
As a child, Paula Smith, from Ipswich, remembers her grandmother talking with sorrow of her younger brother Henry Metcalf, a 19-year-old Royal Marine who had served aboard Vanguard for just two months when he died.
She said: “They never found him and she never made it to Scapa Flow. I’m doing this in her memory as well as his.”
The wreath-laying ceremony was followed by a service of commemoration at Lyness Royal Naval Cemetery in Hoy, where 41 of the ship’s crew were buried.
Five-year-old Harry Remers, from Midhurst in West Sussex, laid a wreath on behalf of all the descendants.
His great-great-uncle, Lieutenant Reginald (Rex) Elgood, was among those who died.
The events culminated with a special night watch service at St Magnus Cathedral in Kirkwall, timed to mark the moment the Vanguard went down – 11:20pm.
Although the cause of the explosion has not been proven, the accepted explanation is that a fire started in a fuel compartment next to one of the battleship’s armaments magazines, triggering explosions that blew the ship apart.