The race for Sydney to Hobart line honours is set to go down to a four-way River Derwent battle in what could be one of the tightest finishes in race history.
Supermaxis Comanche, Black Jack, Wild Oats XI and Infotrack are heading down Tasmania's east coast and were on Thursday evening separated by as little as four nautical miles.
"It is by far the closest race ever. I think it will go all the way to the finish line," Mark Richards, skipper of eight-time winner Wild Oats XI, said.
Lighter air specialist Black Jack looms as a real threat to defending line honours champion Comanche.
A Friday morning finish is tipped but it could be later depending on conditions, which have been tough to predict.
"It's unusual to have four quite different boats all in the same patch of water," Black Jack navigator Tom Addis said, hoping for calmer conditions.
"We're really strong in about eight knots or less. If it's more than eight knots, the more powerful boats can go faster. We're hoping for a shut-down."
The lead changed several times on day two as conditions eased after the quartet crossed Bass Strait.
"One boat gets a mile ahead, then the rest come back," Cruising Yacht Club of Australia (CYCA) commodore Paul Bellingham said of the day.
"I think they are all trying to find that particular advantage, trying to sail to their own particular advantage.
"We know that Comanche likes the heavy winds. Historically Black Jack and Wild Oats XI are light-wind boats with narrower hulls."
Wild Oats XI was first past the post last year but sensationally lost line honours to Comanche after copping a time penalty for failing to keep clear while tracking earlier in the race.
All but four of this year's 85 starters are still at sea, with supermaxi Scallywag pulling out early after its bowsprit broke off.
The 74th edition of the famous race also took a moment to remember the death of six competitors 20 years ago.
Mike Bannister, John Dean, Jim Lawler, Glyn Charles, Bruce Guy and Phil Skeggs died during the 1998 Sydney to Hobart in wild weather.
A radio message, the same words spoken at a 1998 service for the men, was broadcast to the fleet on Thursday afternoon.
"May the everlasting voyage you have now embarked on be blessed with calm seas and gentle breezes," radio relay boat official David Kellett said.
Five boats sank in fateful race, with only 44 of the 115 starters finishing and 55 sailors rescued from heavy seas.
Midnight Rambler, the yacht that won handicap honours in 1998, is leading this year's hunt for the same honour.
It is scheduled to cross the finish line on Saturday morning.
