A Kiwi has pleaded guilty to arson after she deliberately doused her former partner’s boat in petrol and set it alight, causing an eye-watering $400k damage bill.

The 40ft yacht was destroyed after it burst into flames in September 2022 while moored in Pioneer Bay, Airlie Beach in Queensland’s Whitsundays, according to the Australian Daily Mail.

The pair sailed from New Zealand to the Whitsundays before the arson attack.

The Herald previously reported that the blaze caused a gas bottle to explode on the vessel, with locals hearing the loud bang ring out across the quiet resort town.

The fire could be seen from suburbs away, with emergency services spending several hours working to put it out.

Sandra Lee Cootes pleads guilty

Footage in court showed the then 54-year-old New Zealander, Sandra Lee Cootes, as she threatened to burn the yacht by holding a flame over it, The Courier Mail reported.

The burning item she held dropped into the petrol and the flames rapidly spread.

“Jump in the water now … do you want to die, get in the water now”, local police officers told Cootes.

She was then rescued by police and taken to hospital with serious burns.

She appeared in Mackay District Court via videolink earlier this month and pleaded guilty to arson as a domestic violence offence.

The court heard Cootes and the victim had been in a rocky 18-month relationship.

In the days leading up to the arson , she was hospitalised for taking pills, The Courier Mail reported.

She was released from hospital on the morning of the offence, where she met up with her former partner and an argument escalated, which led to the blaze being ignited.