The minute's silence fell at Trinity Square on Tower Hill at 11am, the precise moment as the nation's Remembrance at the Cenotaph in Whitehall.
It followed the bells of All Saint's Tower Hill ringing out in tune the seafarers' Eternal Father Strong to Save hymn traditionally associated with the maritime services and those in peril on the sea.
It was also one of the hymns sung by VIP guests and the public who packed the square opposite the Tower of London in an emotional 40-minute service.
The Merchant Navy memorial marks the 50,000 seafarers who have no grave but the sea.
Their only commemoration is at Tower Hill. Every ship that went down and the names of every seafarer who perished are recorded on its tablets in stone.
We Will Remember Them