A mother who lost her daughter in 2003, in a sailing accident, is reported as saying that the holiday company treated her "like flotsam" during her 13-year battle for justice.
11-yo Laura Morgan of Nottinghamshire died at a Sunsail resort when she was trapped under a catamaran.
A Greek court awarded her mother Lynne an undisclosed compensation sum last week, but she said Sunsail did not show "an ounce of compassion".
TUI Group sailing holiday specialist Sunsail said safety was a priority and it regretted the "protracted process".
A Greek court found three employees of UK-based Sunsail guilty of causing death by negligence in 2006.
One was cleared on appeal. The two others were given suspended prison terms after another hearing in 2007. Their appeals were rejected in 2010.
Morgan told the BBC that a total of 13 court hearings had been held into her daughter's death, but Sunsail had shown "complete contempt for Laura, myself and my family".
"It has been absolutely horrific because for 13 years I have had to repeatedly go over and over all the details of how my beautiful daughter died.
"Grief is a very powerful emotion and I became more and more determined to fight for the truth to come out and for justice to be served in a moral as well as judicial sense.
"Laura's death never should have happened. Sunsail were operating in a very unprofessional, laissez-faire manner out in Greece."
The civil case for damages was launched in Greece in 2011 and was resolved last week, Morgan said.
Sunsail said in a statement that it operated within "the stringent safety guidelines" set out by the Royal Yachting Association and safety was "an absolute priority".
"We will always deeply regret the distress that this protracted process has undoubtedly caused for Laura's family and we are aware that this matter has taken a number of years to reach resolution," the operator said.
It added that the claim for compensation was originally pursued by the family through the Greek courts, and that Sunsail had "always acted in accordance with any orders received" from the courts.
A week-long inquest in Nottingham in 2012 heard that Laura's catamaran was caught by the wind and turned over on its side at a resort in Vounaki, near Paleros.
She became trapped underneath when her trapeze harness - which allows sailors to lean out to help steer the boat - was tangled in the rigging, the inquest heard. Morgan said:
"I have lost one of the most precious things in my life... and it should never have happened. Sunsail has treated me like a piece of flotsam in all of this with no regard to my emotions and my feelings."
For reports on other cruise ship accidents see at CruiseMinus.com