The 11 cases of coronavirus on a ship docked off the coast of central Queensland is likely to be the Delta variant, Maritime Safety Queensland says.

General manager of Maritime Safety Queensland Angus Mitchell said the affected ship, the Pan Europe, is an LNG tanker which is at anchor near Gladstone.

"We're still waiting on that serology to come back, but it certainly does look like Delta is likely and that's really some advice from Health around the spread of infection," general manager Angus Mitchell said.

He said it was encouraging that most of the crew – 23 out of 26 were vaccinated.

Mr Mitchell said there was no risk to the community in Gladstone, as the ship did not require port pilots to dock and the only people onboard have been health personnel in full PPE.

He said, usually, seafarers who tested positive to COVID-19 were transported to hospitals for treatment, but the ship was remaining off the coast of Gladstone for now with the situation being monitored.

Mr Mitchell hoped the seafarers would not become sick enough to require hospital transport, given the large number who were vaccinated.

Chief Health Officer Jeanette Young said this morning that if healthcare was required, seafarers would be transported to the Sunshine University Hospital for treatment.

Gladstone Mayor Matt Burnett said the tanker arrived off the coast of Gladstone on August 3 from South Korea, but symptoms were reported in transit on July 31.

Mr Burnett said the ship had not been into port and shipping schedules had been adjusted, with other vessels taking on product.

Mr Mitchell said the transmission likely occurred during a crew changeover in Japan, and before the ship arrived in Queensland waters.

"This is one of many ships that we've had to deal with over the past 18 months with COVID on board," he said.

"We got a report earlier on in the week prior to it coming into Queensland waters that a number of the crew were showing symptoms associated with COVID so as is the standard precaution we put the vessel to anchor, we get health personnel onboard to do testing, and then we await the results."

Mr Mitchell said he expected very little impact on Gladstone's Port and on LNG shipping.

"Adjustments will need to be made, as they are with any vessel that gets disrupted, whether that's disrupted through weather, with COVID in this instance … It's a normal part of business activities in the port to make sure you can plan and work around any disruptions."