Hundreds of people turned out to see Happy Feet's sixth and final medical procedure at Wellington Zoo before the emperor penguin begins his journey back to the wild tomorrow.

An estimated 1700 visitors craned to see vet Lisa Argilla complete a medical check ahead of Happy Feet's trip, and watch a GPS transmitter being attached to his feathers.

Visitors were rotated past the viewing area in five minute blocks, so that everyone could see the sedated Happy Feet for the last time and say goodbye.

Ms Argilla, who has been looking after Happy Feet since his appearance on Peka Peka Beach, said she had become quite attached to the little guy - but was happy he would be going back where he belongs.

The bird arrived at the zoo weighing 22 kilograms, although it was estimated that up to three kilos of that was sand that had to be removed. He now weighs a healthy 27.4kg.

He will leave Wellington on Monday for a four-day voyage aboard the National Institute of Water and Atmospheric Research survey ship Tangaroa, before being released into the ocean near Campbell Island.

Dr Argilla will tend to the bird while he is on the boat, along with specially trained Niwa biologists Dan MacGibbon and Neil Bagley.

- © Fairfax NZ News