A dozen people have contracted COVID-19 on one of the first cruise ships allowed back into Western Australia since the pandemic began.

Ten passengers and two crew have tested positive aboard the Coral Discoverer, which arrived in Broome early on Monday.

The vessel, carrying 61 passengers and 30 crew, had completed a 10-day voyage from Darwin.

A spokesman for the ship's operator, Coral Expeditions, said all guests and passengers were triple-vaccinated in line with WA requirements.

The positive guests and their close contacts had isolated and some had been transported to designated hotels in Broome to finish their isolation periods.

"All of the guests were either asymptomatic or had mild symptoms," he said.

Small cruise ships carrying no more than 350 passengers and crew have been permitted to enter West Australian waters since April 17.

"Maritime vessels are permitted to allow positive cases to disembark and move to suitable accommodation to complete their isolation requirements," a WA Health spokeswoman said on Monday.

"There are strict guidelines in place which outline the infection prevention and control measures that need to be followed during disembarkation and transport.

"All precautions will be taken to ensure the Broome community is protected."

WA Health on Monday reported 5639 COVID-19 cases and the death of a man in his 80s.

There are 240 cases in hospital, including nine in intensive care.