Shark biscuit
Australian SlangDefinition
Australian slang for a surfer or bodyboarder—especially a beginner or child—so called because they’re seen as “bite-sized” for sharks.
Examples
"The surf was tiny—perfect for the shark biscuits taking their first lesson near the flags."
"He used to be a total shark biscuit on a boogie board, but now he’s catching green waves on a shortboard."
"The lifesaver kept a close eye on the little shark biscuits bobbing in the shore break."