'Hard to understand': Sydney to Hobart crew cop 'devastating' news

Ichi Ban has become the first yacht to win back-to-back Sydney to Hobart handicap honours in more than 50 years after rival Celestial copped a "devastating" time penalty.

Celestial was penalised 40 minutes after a protest lodged by overall winner Ichi Ban and the race committee for breaching race communication rules was upheld on Friday morning.

'SHOCKING': Cricket world in disbelief over sad Quinton De Kock news

'MIX OF EMOTIONS': Sam Stosur confirms huge Australian Open rumour

Celestial led Ichi Ban in overall standings after the pair arrived in Hobart on Wednesday mere minutes apart.

Celestial skipper and owner Sam Haynes said while he respected the international jury's decision it was a "very, very difficult penalty to swallow".

"As far as I'm concerned, the decision stands. There's nothing I can do about that," he told reporters.

"It's a devastating moment. I've been trying to win this race for 10 years."

Both protests related to a race rule that requires competitors to keep constant radio contact.

However, Haynes said his crew didn't know it was unable to hear the radio and always raced with a safety-first approach, insisting the issue was not limited to his yacht.

"The problems with communication in this race were not just isolated to Celestial," he said.

"I've been sailing bluewater racing now for a long time. It happens continuously."

The race committee was notified by the Australian Maritime Safety Authority (AMSA) on Monday night that a crew member aboard Celestial had activated a personal locator beacon (PLB).

The committee was unable to contact Celestial initially and called on Ichi Ban, which was sailing nearby, to contact the yacht by VHF radio.

Ichi Ban made contact about 90 minutes after the initial AMSA notification after releasing a flare which caught Celestial's attention.

Ichi Ban lodges protest against Celestial

It was confirmed the PLB had been activated accidentally and AMSA was told to stand down search and rescue aircraft.

The jury found Celestial did not hear any attempts to contact her on VHF during the incident.

It ruled Ichi Ban did not alter its course as a result of the incident but did prepare and deploy two flares which "temporarily affected her performance".

The race committee noted 12 other PLBs were accidentally activated during the race and in each case the boat responded within 25 minutes.

Haynes said he thanked Ichi Ban for setting off the flare and alerting them to the problem.

"I thought it was a gesture of good sportsmanship, and it was. But I didn't realise we were going to be a) protested by them or b) be protested by the racing committee," he said.

"It's not actually good for the sport to have these technicalities, things that people are really going to find hard to understand.

"This is the most important race in Australia, potentially one of the most important races in the world, and this is the way it's gone."

Ichi Ban arrived in Hobart with its protest flag raised but skipper Matt Allen didn't initially indicate whether one would be lodged.

It could become the first yacht to win back-to-back overall wins in 57 years.

In 2017, a successful protest over a near collision resulted in supermaxi Wild Oats XI copping a one-hour penalty and losing line honours to LDV Comanche.

with AAP

Click here to sign up to our newsletter for all the latest and breaking stories from Australia and around the world.