Around 200 people gathered on HMS Belfast on Tuesday for a memorial service to mark the second anniversary of the Bali bomb.
Russell Ward, a British fireman who was caught up in the Bali bombing, dropped a wreath of white lilies into the Thames following the service.
Meanwhile a tall ship manned by a crew of Muslims, Jews, US and British youngsters moored alongside HMS Belfast to promote understanding between cultures.
The trip, which set sail from Southampton two weeks ago was organised by Encompass – The Daniel Braden Reconciliation Trust, a charity started by the family and girlfriend of Daniel Braden who died in the bombing in Indonesia.
Mr Braden, from Brighton, East Sussex, was one of the 202 victims of the attack on 12 October 2002.
The 48-strong crew aboard the ship, called Prince William, included six Israeli Jews, one Israeli Arab, five Palestinians, nine Indonesian Muslims, nine British Muslims from Derby and Bradford, and five people from the United States, with the remainder from around the UK.
• A year ago Prince Charles attended a service at Southwark Cathedral to mark the first anniversary of the bombing.