The mist hung low over Taiaroa Head, meaning Celebrity Solstice and her 2850 passengers and 1250 crew, and Seabourn Encore, with 604 passengers and 400 crew, were unable to visit.
While the cancellations mean tourist enterprises like Dunedin Railways, Olveston and others would lose out, Dunedin i-Site visitor centre manager Louise van de Vlierd said the two ships were the first cancelled this season.
That compared with this time last season, when six ships had been cancelled due to weather.
The decisions to turn away were made by both ships in the early afternoon, after they waited in vain for the mist to clear.
The ships ''waited and waited'' before leaving.
''They didn't make the decision lightly, they really did want to come in.''
While Port Chalmers was sunny, the mist had hung in around Taiaroa Head.
The Regatta, with 684 passengers and 386 crew is due tomorrow.
Ms van de Vlierd said she would ``keep my fingers crossed'' the mist did not affect that vessel.
Diamond Princess and Golden Princess, both larger ships, are expected on Friday, though the forecast is for cooler weather by then.
MetService meteorologist Tuporo Marsters said the fog, which had stretched as far up the coast as Kaikoura, had drifted offshore by 2.30pm.
The mist was caused by warm air blowing over the colder ocean.
