A large crowd at the Warrnambool breakwater was mesmerized as a whale frolicked for several hours on Sunday.
Department of Environment, Land, Water and Planning natural environment programs officer Mandy Watson said most migrating southern right whales visited the south-west from May to October.
However, individuals have previously been sighted in other months.
She said photographs of the whale showed it was a sub-adult southern right whale.
"Sightings of southern right whales were also reported near Phillip Island late last week," Ms Watson said.
"It's unusual to see a southern right whale in early November.
"Given the time of year, these whales will most likely be heading to sub-Antarctic waters to feed."
Visitors and residents alike headed to the breakwater on Sunday to see the whale in action.
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