The extent of the Wahine disaster this day 50 years ago took Wellington by surprise.

That's how former Wellington Harbour Board pilot John Brown remembers the event.

He told Kate Hawkesby he managed to get alongside the ferry before it went down.

Brown says he dropped the harbormaster off to talk to the Wahine's captain.

"And say look we think you are pretty badly damaged, more than what you are telling us, because we had been around the ship to observe the draft and so forth.

"It was only half an hour, or three-quarters of an hour after that they decided to abandon ship."

 LISTEN TO THE FULL INTERVIEW WITH JOHN BROWN ABOVE