The men, who were working on the AdvanFort anti-piracy ship MV Seaman Guard Ohio, are:
Nick Dunn from Ashington, Northumberland
Billy Irving from Connel, Argyll
Ray Tindall from Chester
Paul Towers from Pocklington, East Yorkshire
John Armstrong from Wigton, Cumbria
Nicholas Simpson from Catterick, North Yorkshire
The men, who became known as the “Chennai Six”, were among 35 men detained in October 2013 while working as security guards on ships to combat piracy in the Indian Ocean.
A Facebook post said all 35 had been cleared and their families were “understandably delighted”.
The post said: “The appeal court has today found all 35 men NOT GUILTY we now wait to hear as and when the men will be allowed home to their families.
“This may take some time whilst the authorities decide whether they agree with the outcome or wish to appeal. If they wish to appeal the men might be released from prison but not allowed back to the UK.
“But the families are understandable delighted that finally common sense and justice has prevailed.”
The six men are: Billy Irving, 37, from Argyll and Bute; Nick Dunn, 31, of Northumberland; John Armstrong, 30, of Wigton, Cumbria; Nicholas Simpson, 47, of Catterick, North Yorkshire; Ray Tindall, 42, of Chester; and Paul Towers, 54, of Pocklington, east Yorkshire.
Yvonne McHugh, the partner of Billy Irving, said she was “over the moon” the men had been cleared.
“They’ve all been acquitted, all 35 of them,” she said. “We are just waiting to hear how soon they’ll be home. That’s the biggest hurdle we faced and all of them have been acquitted.”
Although the men had been cleared, McHugh said, she had been unable to speak to Irvine as he was not yet out of prison and did not have a phone.
She said: “We just want them home as soon as possible. I’m absolutely ecstatic and feel proud we’ve managed to do this after four years.”