A coroner's found the woman who died while swimming with dolphins off the coast of Picton is likely to have suffered a fatal heart arrhythmia.
Emily Harper was pulled from the water just minutes after the crew of an EcoTours boat noticed her floating oddly while on a dolphin watching trip in October 2007.
The 27-year-old's skin was blue by that stage.
CPR was performed on her straightaway and until the boat docked but paramedics were unable to revive her as well.
She was on the tour with her fiance and his family.
His mother's pointed to drowning as the cause of death but Coroner Christopher Devonport's found it's more likely her death was the result of a heart arrhythmia.