Terry Selwood, 73, had dropped a line at his "usual spot" at Evans Head in New South Wales when the animal launched itself out of the water.
He said the 2.7m (8.8ft) shark landed in the boat, which measured about 5m, and grazed him with its pectoral fin.
Mr Selwood was rescued after radioing for help.
"I was losing a fair amount of blood, I was stunned, I couldn't register what happened and then I thought, 'oh my God, I've got to get out of here,'" he told the Australian Broadcasting Corp (ABC).
"There I was on all fours and he is looking at me and I am looking at him, and then he started to do the dance around and shake and I could not get out quick enough."