People come from all over to see the biggest tourist attraction in Auckland. Paris has a tower, San Francisco has a bridge, Auckland has an old sewage tank. Down under the ground you go, and for 30, 40 dollars you get to take a good old look around. Of course, it’s a bit more than a sewage tank. It has penguins. It has a gift shop. It has a perspex tunnel that makes it feel like you’re under the sea. And, it has sharks.

People love Kelly Tarlton’s. I couldn’t count how many times we took our daughter and she stood patiently in line for an hour or more. Much more patiently than me. Years later, she told me the look I sometimes get is, “your Kelly Tarlton’s queue face.”

But what a great object lesson. With a bit of imagination you can go so very far. I want to go from one side of the harbour to the other. My great dream of nearly 20 years now is an underwater tunnel between the picturesque seaside village of Devonport and the city. An under-harbour tunnel connecting us to the bottom of Queen Street, with one of those travellator things you get in big international airports. And all under a perspex cover, like Kelly Tarlton’s.

I have been banging on about this idea forever. I enthused about it to the mayor of Auckland. His eyes glazed over. I proposed it in a debate with our Prime Minister. She didn’t say no, reader, she didn’t say no. I live in hope.

And, I offer this as a little object lesson in how a rough little nub of an idea can turn into something more through the magic of collaboration. As soon as I first wrote about it (at this point all I imagined was an underwater travellator in a tunnel) people were helpfully suggesting how to make it better.

“I can’t help but wonder how fast you could make a travellator that long,” one said. “Obviously you’d need several abutting travellators of graduating speeds to keep the acceleration from breaking people. The same in reverse at the other end... could you create an artificial tail wind to help negate the air resistance?”

It turned out that very question was already being tackled elsewhere. In France - where they call it a trottoir - I found they had one at a station interchange inside the Paris metro. It was 180 metres long and accelerating up to 11 km/hr. Hell, that’s nothing, I thought. We’re bungee jumpers here. I’d say we’re good for hanging on at 30km/hr, no worries!

Another said: “Maybe you should get Kelly Tarlton’s in on the action and make the tunnel perspex. You’d probably want to clean up the scum that is our harbour and you’d need some clever robot thingy to keep it clean, but wouldn’t it be cool to have the harbour as a sightseeing attraction?”

This was the genius moment for me. Ever since, I have believed in the power of perspex. That particular responder also said: “Of course you’d want to make the harbour a marine reserve to get the fish back but seriously how many people do you know who are silly enough to eat fish caught in the inner harbour?”

Years went on. I wrote about it; I talked on the radio about it; I bored New Zealand about it. “We love it,” said a few people. “Have another drink” said others. Various people said to me: “Well okay, but how will you see anything in that murky water?” And then I thought: no worries. You wrap the tunnel in another layer of perspex, and you fill that up with warm water and fill it up with beautiful tropical fish. A beautiful Samoan reef here in our chilly waters.

Imagine it. You just stroll whenever you like from one side to the other. You get to the bottom of Queen St, you just keep on rolling, to Devonport. No need for a multi-billion-dollar harbour crossing, just a beautiful tourist attraction to stroll across or glide through on your e-bike. My liberal-minded friends also like the idea that if the coming referendum takes us in the direction of legalised weed, well, people will be down there in the perspex with the tropical fish all day long, my dudes.

You may say I’m a dreamer, but I’m not the only one who’s watched The Castle. The story of life is the way we can climb down into a sewage tank, take a look around and say: “Okay, here’s what we can do. Who’s got a tape measure? Who knows about sharks? And do we know anybody who makes perspex?”

Just imagine!

About the author

David Slack is an author, radio and TV commentator and speechwriter. He established the website speeches.com, and has published several books including ‘Bullshit, Backlash and Bleeding Hearts’, exploring Treaty of Waitangi issues, and ‘Bullrush’, a social history of the popular children’s game.