Public health officials revealed they were also concerned about the rising number of infections associated with a music festival at Launceston with a total of 25 linked to the event so far.
According to Tasmania's Premier Peter Gutwein, the infected on Coral Discoverer (owned by Coral Expeditions Australia) had been removed from the ship.
~60 passengers and 30 crew remain onboard and are being tested for COVID with contact tracing to continue over the next two days.
The boat activated her COVID response plan to manage the outbreak as well as to ensure no broader risk to the wider community.
Deputy Director of Public Health Scott McKeown said they would "continue to work closely with the vessel to ensure that any risk on board is being managed and to ensure there is no broader risk arising from the two cases that have occurred."
For more Coral Discoverer incidents and accidents see the ship's CruiseMinus page.