Police are thanking the public for a quick response to a sinking boat on the Huon River on Monday afternoon.
An 8-metre wooden sail craft upturned and began sinking; police attended with support from maritime vessels near Port Huon.
All four of the vessel's occupants were wearing lifejackets and were rescued, two of them later taken to the Royal Hobart Hospital for observation.
"The incident highlights the importance of personal marine safety and being adequately prepared by using personal floatation devices," said Acting Inspector Peter Borish.
The cause is under investigation.