NSW yacht Celestial V70 has toasted overall victory in the Sydney to Hobart yacht race after piercing "nuclear" weather across Bass Strait.

Skipper Sam Haynes and his crewmates were presented with the Tattersall Cup on Sunday afternoon after being named provisional winners of the handicap competition.

The 79th edition of the 628 nautical mile event was hit by tragedy on its first night when two competitors died at sea in rough weather.

"We are very conscious of the events that have occurred in this race," Haynes said.

"It's something that is on the mind of myself and the crew. We are very ... saddened and we are thinking about the families of those involved."

Veterinarian Haynes chartered the Volvo 70 with a view to reclaiming the Tattersall Cup after winning the race on handicap in a smaller boat named Celestial in 2022.

He described conditions for the yacht as "nuclear" across Bass Strait.

"It was a race forecast that was challenging (but) conditions that suited this type of boat," Haynes said.

"The stretch across Bass Strait was most difficult for us - but we negotiated that transition between the northerly breeze and into the front.

"(With) this boat, we have a yacht that's powering at a high speed ? it spears through waves, it doesn't skip across them.

"From our experience (in the race) it was absolutely blasting."

Haynes competed in his 13th Sydney to Hobart with the majority of the crew from the 2022 win and credited an inshore route off Tasmania's east coast for the success.

"It's just so much joy ... being able to perform at that level and get to the point where you're able to hold that trophy once more," he said.

Celestial V70 was second across the line at 5.10am on Saturday, behind back-to-back line honours victor LawConnect who finished at 2.35am.

Twelve yachts of the 104-strong starting fleet had finished the race at 5pm on Sunday, with 62 still at sea.

There have been 30 retirements in weather that hit 40 knots, including line honours fancy Master Lock Comanche and 2023 overall winner Alive.

Roy Quaden, 55, and Nick Smith, 65, died off the NSW south coast after being hit by on-board equipment on yachts Flying Fish Arctos and Bowline respectively.

Race organisers have pledged an investigation into the deaths - the first since 1998 when six sailors were killed, prompting mass safety reforms.

Experienced skipper of MWF Kayle, John Whitfield, said winds were 10-15 knots on Sunday morning, making for "champagne" conditions off Tasmania's coast after taxing earlier racing.

Whitfield, in his 30th Sydney to Hobart, said his crew had to drain their engine twice after it became flooded.

"We've had plenty of water across the bow and plenty down below," he said.

"We are thinking about those who lost their lives. We're definitely looking forward to reaching Hobart."