The man who is an Ethiopian national in his thirties was part of the crew on a cargo ship that was in the port last Thursday.
He, along with two others, went ashore to go to a local bar.
However, the man did not return with the group.
The cargo ship has since left port.
Yesterday and today members of Fenit Lifeboat and Glenderry Coastguard searched the area but were unsuccessful.
Valentia Coastguard tasked Shannon Coastguard Helicopter to the scene to help with the search.
The search has since been stood down for the day and will resume tomorrow.