Photo shows three rowing eights, one in the foreground of the photo and two further along the river with several smaller vessels around them. Identified as the Kings Cup rowers on the River Murray at Murray Bridge.
In 1949, the Australian Interstate Rowing Championships, including the King's Cup (Men's Eights), were held at Murray Bridge. New South Wales won the championship from Western Australia, Victoria, Tasmania, South Australia, and Queensland. The date of this photo is unknown but based on the original catalogue listing believed to be the 1949 race.
The Murray Bridge Rowing Club won several Kings Cup races in the 1920s and in 1924 represented Australia in Paris.