Search for Vic fisherman continues in dark

The search for a Victorian fisherman missing for more than four days will continue through the night after his kayak was found.

Junichi Yoshimura's distinct yellow kayak was found in Port Phillip Bay on Monday, more than 60km east of the Altona boat ramp where the 41-year-old's car was parked.

The Japanese national was believed to have left his Torquay home to go fishing early on Thursday but did not take a wetsuit or life jacket.

Colleagues raised the alarm after the baker failed to turn up for work on Friday, sparking an air and water search.

Authorities said Mr Yoshimura often went fishing but it was unclear which direction he had headed.

Water police will continue searching the bay throughout the night.