SYDNEY — Monaco Yacht Club super maxi Black Jack held a 18-nautical-mile lead over fellow maxi SHK Scallywag on Monday in a Sydney to Hobart race hit hard by retirements of nearly half the fleet due to heavy seas.

More than 24 hours into the annual race from Sydney Harbor to Hobart on the island state of Tasmania, Black Jack was estimated to finish the race by Tuesday evening based on current weather conditions. The race began Sunday.

Stefan Racing was in third place and the race’s third super-maxi, LawConnect, was in fourth.

There were only 42 boats remaining in the race from the original start list after the high seas and winds decimated the fleet overnight Sunday night. A total of 28 yachts had retired since the race began.

Sailors returning to Sydney said it was heavy seas that caused most of the problems rather the southerly winds they were pushing into.

“The breeze was 33, 34 knots, which is not that bad,” said No Limit crew member Declan Brennan, whose boat retired after one of the crew sustained a dislocated shoulder.

“Its curious, it wasn’t angry conditions it was a just a very short, sharp seaway. The seaway was so inconsistent we were just bouncing around all over the place.”

There were no other reports of injuries to crew members on other boats.

Last year’s race was canceled the week before it was due to start because of coronavirus-related quarantine issues, but the 2021 edition is proceeding with mass virus-testing protocols in place. Skippers have been told boats must immediately retire from the race if a crew member receives a message from health authorities saying they have tested positive for COVID-19.

The 628 nautical-mile race (1,170 kilometers, or about 720 miles) sails from Sydney down the south coast of New South Wales state and across to Hobart.

In 2017, Comanche set the race record after finishing in 1 day, 9 hours, 15 minutes and 24 seconds.