Il Nuovo Postiglione - Two killed in treacherous Sydney-Hobart yacht race

Both crew members -- on Flying Fish Arctos and Bowline -- were hit by booms as the yachts raced southwards along the New South Wales coast after setting off from Sydney Harbour on Boxing Day.

Other crew tried to revive them, but were unsuccessful.

The race committee said it could not provide further details of the deaths as police were investigating and some family members were yet to be contacted.

"Our thoughts are with the crews, family and friends of the deceased," it said in a statement.

New South Wales police said the boat crews had notified them of the two deaths during the night.

Strong winds were powering the yachts at the time of the sailors' deaths, said David Jacobs, vice commodore of the Cruising Yacht Club of Australia.

"The lead boats were experiencing speeds of between 25 and 30 knots so they're travelling extremely fast. The sea was not unusually large from the information I have received," Jacobs told reporters.

- 'Devastated' -

The yacht club will open an investigation to help improve safety in the event, he said.

Jacobs added that the deaths would hit the racing community hard.

"On a boat itself they train together, live together, cook together, they do everything together. It would be devastating, as we are devastated," he said.

Gale-force winds and high seas had been forecast for the 628-nautical mile event, which ends in the Tasmanian state capital Hobart after the fleet tackles the notorious Bass Strait.

But this was not an "extreme" forecast, Jacobs said.

"These fleets can handle those winds easily. They are ocean racers, they are used to the winds," he said.

Weather is a critical factor in the race, first held in 1945, with winds and conditions often changing rapidly.

Six men died, five boats sank and 55 sailors were rescued in 1998, when a deep depression exploded over the fleet in the Bass Strait.

So far 16 yachts have pulled out from the initial fleet of 104, Jacobs said.

Alive, last year's overall winner of the Tattersall Cup, which takes into account boat size and other factors, was one of the first casualties, retiring with engine issues.

- Race favourite retires -

In a major setback, race record holder Comanche retired with mainsail damage, leaving the door open for supermaxi rival LawConnect to win line honours for the second straight year.

Comanche, which surged over the finish line in one day, 9 hours, 15 minutes and 24 seconds to set a new mark in 2017, was leading when she retired.

LawConnect held a lead later on Friday morning of more than eight nautical miles over its nearest rival Celestial, closely followed by Wild Thing.

Wild Oats, which has twice won the race -- the last time in 2014 -- was another casualty, with rigging damage.

E.Danieli--INP