There have been scenes of celebrations after Comanche claimed its third line honours victory in the Sydney to Hobart yacht race.

Key points: Comanche finished in a time of 1 day, 18 hours, 20 minutes and 24 seconds

Comanche finished in a time of 1 day, 18 hours, 20 minutes and 24 seconds The supermaxi led for much of the race, but briefly lost the lead to both Scallywag and InfoTrack

The supermaxi led for much of the race, but briefly lost the lead to both Scallywag and InfoTrack After earlier predictions of a Saturday afternoon finish, Comanche crossed the line about 7:30am AEDT

Comanche crossed the line about 7:30am, with a race time of 1 day, 18 hours, 30 minutes and 24 seconds.

Skipper Jim Cooney celebrated by spraying his crew with champagne, but when it came to the long standing practice in yacht racing of honouring a victorious skipper by throwing him in the water, his son James took his place.

Loading

Comanche was in the leaders' pack throughout the race, taking what the ABC's Chris Rowbottom as a "gamble" by going out wide, further away from the shore, early on to find a breeze.

On day two, the three-time line honours winner lost the lead at various times to Scallywag and InfoTrack in what was described by commentators as a "game of cat and mouse".

But Comanche's early tactical manoeuvre paid off when favourable north-westerly winds helped the fleet pick up speed overnight, pushing forward forecasts of a Saturday afternoon finish.

Comanche was followed into the River Derwent by its fellow supermaxis, with InfoTrack crossing the line second.

Nine-time line honours winner Wild Oats XI and Scallywag were 38 seconds apart to claim third and fourth spot respectively, with Black Jack in fifth.

Comanche took its first line honours win in 2015, and its second in 2017 after Wild Oats XI, which had crossed the line first, was penalised.

Skipper devastated after shark crash slowed race

Scallywag's skipper says he's gutted by the supermaxi's fourth placing. ( AAP: Dean Lewins )

Scallywag led for much of day two before losing pole position in the afternoon, and ultimately finishing fourth.

Skipper David Witt said it was a collision with a shark that slowed Scallywag's pace, adding the crew was gutted.

"We had a shark hit the rudder, broke its back on the rudder, and the boat wiped out," he said,

"We had to pull sails down, back it up and get the shark off and that lost us all the places.

"Then to come back and try to beat Wild Oats at the death there with 30 seconds or something in it — I dunno, it's killing me this race."

Comanche previously won line honours in 2015 and 2017. ( AAP: Dean Lewins )

The 2019 Sydney to Hobart fleet started with 157 yachts in Sydney Harbour on Boxing Day.

Two yachts — Faster Forward and Hollywood Boulevard — retired at port, and Minerva retired at sea.

In addition to the line honours victor, an overall winner is also calculated once handicaps are applied.