Koa has withdrawn from the Sydney to Hobart Yacht Race only two weeks after claiming overall victory at the last long-form event before the bluewater classic.
The NSW-based TP52 won the Cabbage Tree Island race from Sydney to Port Stephens and back on December 4, beating 64 other starters to claim a handicap victory.
Koa, Hawaiian for "strong warrior", also placed second at this year's Flinders Islet Race and fifth at the Bird Island Race, both on handicap.
She was set to be one of nine TP52s, the same model as last year's overall winner Celestial, contesting this year's Hobart.
But on Thursday, Koa's crew informed race staff the boat would pull out of the race, declining to elaborate on the reason for the withdrawal when asked by race staff.
Koa's scratching follows that of the Jim Cooney-skippered Willow, Wots Next and Hasta La Vista in recent days and leaves the fleet at 103 starters ahead of Boxing Day.
