Maritime union RMT remembered the 193 crew and passengers who lost their lives in waters off Zeebrugge on 6 March 1987 when the ferry Herald of Free Enterprise capsized.
National Secretary Darren Procter paid tribute to those who were lost in the tragedy at a memorial in Dover.
RMT general secretary Mick Lynch said: “We pay tribute to the memory of the crew and passengers who died in the Herald of Free Enterprise disaster and extend our condolences to the community in Dover who were affected by this avoidable tragedy.
“RMT is continuing to support high maritime safety standards for all seafarers and passengers using Channel ferry services, despite P&O’s efforts to speed up the race to the bottom by sacking all its British seafarers two years ago.
“Wherever employers try to undermine safety, our union will act to defend our members best interests.”
The Townsend Thoresen ferry Herald of Free Enterprise tragically capsized moments after leaving the Belgian port of Zeebrugge on the night of 6 March 1987, and 193 passengers and crew lost their lives.