Vic kayaker still missing after search

The water search for a kayaker missing in Melbourne has been called off until first light, but crews will continue to scour the shoreline throughout the night.

Water police, helicopters, and SES crews spent Saturday searching Port Phillip Bay for missing 41-year-old Junichi Yoshimura.

The Japanese national was reported missing by his colleagues on Friday night after the baker failed to turn up at work.

Police found Mr Yoshimura's car next to the Altona boat ramp but there was no sight of the 41-year-old or his bright yellow kayak.

It's believed Mr Yoshimura left his Torquay home about 5am on Thursday to go fishing but did not have a wetsuit or lifejacket with him.

"We're now concerned because he may have been missing for as many as 40 hours on Port Phillip Bay," Sergeant Matt Henderson told reporters on Saturday.

Crews have been conducting a search between Altona, Williamstown, and Point Cook with the aid of nine vessels and helicopters.

The water search has been called off until first light on Sunday, but the shore search will continue throughout the night, a Victoria Police spokeswoman said.

"We're looking to see if he's made it to shore or gotten into difficulty there," Sgt Henderson said on Saturday morning.

"We haven't seen or heard any indication of him since he left the boat ramp."

Authorities say Mr Yoshimura often went fishing but it's unclear which direction he was headed on Thursday.

It's hoped a member of the public may have spotted Mr Yoshimura as he set out from Altona boat ramp in his kayak.