Forecast gale force winds will batter the nine hardy crews tackling the Melbourne to Hobart Westcoaster.
The most treacherous of the three races departing from Melbourne on Friday, the Westcoaster fleet is likely to confront swells above five metres as they travel off Tasmania's coast, generated by 30-40 knot winds.
The forecast deterred two boats from attempting the races to Hobart along the west and east coasts.
Shamrock and Hush will instead sail the Melbourne-Launceston race in what the Ocean Racing Club of Victoria called "strong seamanship decisions".
Another, Weekend Option, withdrew from the Launceston race after suffering damage in the Boxing Day Dash.
At 3pm on Friday 27 yachts left the start-line off Portsea on the Mornington Peninsula for the Tassie Trio races.
With a good crowd watching in glorious sunshine, Simply Fun was first around the Queenscliff mark to pass through the heads and into Bass Strait.
Contesting the Melbourne-Launceston race, Simply Fun and its competitors are likely to miss the worsening weather with a benign overnight forecast and projected finish of before lunch-time on Saturday.
Sixty-six footer Gusto and Shamrock were hot on Simply Fun's heels as they sailed past Cape Schanck and into Bass Strait on Friday night.
The Westcoaster fleet was led by Extasea as they took a more easterly route, with the smaller Tasmanian boat Whistler leading a pack of seven boats as they sailed past Anglesea.
XLR8 comfortably led the Eastcoaster race ahead of Young Ones as they sailed past Phillip Island on Friday night.
