The Second World War aircraft is similar to those which operated Iceland’s first international air link - to Largs Bay in 1945.
The former submarine-hunting aircraft, G-PBYA, will leave the Ayrshire airport again tomorrow for the Reykjavik Air Show at 1pm.
The Catalina was used as a firefighting aircraft in Canada after the war.
It is now based at Duxford airfield near Cambridge and owned by Plane Sailing Air Displays.
Icelandair later transferred flights to Glasgow, which currently operate three times a week.