Champion supermaxi Wild Oats was struck by lightning while it underwent final preparations out of the water for the Sydney to Hobart.
Wild Oats was in her cradle at Woolwich Dock on Sydney Harbour when a bolt of lightning struck the top of the 45-meter high carbon fibre mast.
Sandy Oatley, spokesperson for the Oatley family, said it has been "a major blow for them on the eve of the big race".
Although it is unclear if any of the yacht's carbon fibre rigging was damaged, the 10 million volt-plus discharge from the lightning destroyed a number of vital electronic instruments.