The measures were announced as eight more crew from the Al Kuwait livestock ship stranded at Fremantle tested positive, bringing the total from the vessel to 20.

The new cases are among the 38 of the 48 multinational crew quarantined in a Perth hotel.

It is not clear if test results for seven port and quarantine workers who boarded the ship after it docked last week have come in.

The health department says only five were considered close contacts and there are no positive results to date.

Premier Mark McGowan says the cases on the vessel, which sailed from the United Arab Emirates on May 6, did not mean the state couldn't move to phase three of easing restrictions as there is no community transmission.

The eased restrictions will commence next Saturday, when a two square metre rule will apply to indoor and outdoor venues.

At venues where there are multiple divided spaces, gatherings of up to 300 will be allowed.

The hospitality sector has praised the state government's decision to remove an unpopular rule that licensed venues can only serve patrons alcohol with a meal, but the stipulation they must be seated remains.

Beauty parlours, arcades, food courts, wildlife and amusement parks are among businesses that are allowed to reopen.

Galleries, museums and cinemas can too but patrons must be seated during performances at theatres, auditoriums and concert venues.

Gyms can resume trading but must be regularly cleaned and always staffed.

Full contact sport will be permitted, and playgrounds and skate parks will no longer be taped off.

Significantly, travel will again be permitted in the state's far north if the federal government agrees to remove the biosecurity zone on June 5, but remote Aboriginal communities will remain off-limits.

Rottnest Island, which has been used to quarantine returned travellers, will reopen to the general public.

Perth Zoo will have no patron limit although the 100/300 rule applies to its indoor spaces, including cafes.

"I know it is still not perfect but we are moving ahead," Mr McGowan said.

"What's currently in place is affecting people's mental health, it's affecting people's livelihood, it's affecting their self-worth and that's a health impact we have to take account of."

All crew on the Al Kuwait have been tested, including a 10-member skeleton staff who remain on board and have tested negative for the virus.

The new cases bring the number of active cases in the state to 25, with one recovery recorded overnight.

Australian Associated Press