Gondolas are not for real transportation -- especially not for a distance as far away as the airport.

In the many times I have been in Venice I have only taken a gondola twice: Once when I was 19 and was busy hitting on a girl I had met that afternoon and the other, some 35 years later when I wanted to give my daughter a special treat.

They are wonderful for tours of Venice and everybody should try them one time but for real transportation they make very little sense.

You won't have any problem getting a gondola: Go to the Grand Canal right off St. Mark's and there will be dozens of them waiting for a tourist to ask for a trip.