It’s so easy to be preoccupied by the grandeur of all that’s above the surface when crossing Darwin (Garramilla) Harbour. There’s the city skyline that really does gleam in the northern early evening sun, the lush parklands that run along both sides of the sandy and rocky foreshore, the constant traffic of the crossing craft, and the grand expanse of the waterway itself.

We’ve taken off from Stokes Hill Wharf on the Charles Darwin for a sunset cruise with Darwin Harbour Cruises. Even with all the beauty that surrounds this vast stretch as we travel the edge where the harbour meets the Timor Sea, I’m hanging onto the railings of the catamaran to peer through the waves into the deep waters below, trying to see and imagine all that lies beneath.

This harbour, five times the size of Sydney Harbour and 50km in length, has a wealth of stories to share from the many lives it’s lived: from ancient times to the high drama of the last century, and today as Australia’s northern nautical gateway to the world. And I’m here for all of it.

Deep down, there are seagrass beds, famous for how they support dugongs, and patches of coral among the sandbanks. Ruling the roost, however, are the saltwater crocodiles, which offer a stark reminder that while this is a city harbour, it’s still very much in the heart of wild country.

Going way back around 60,000 years or so the area became home to the Larrakia people, the traditional owners of these lands, and the harbour was known as Garramilla. The Larrakia were the ‘Saltwater People’, and many of their Dreamtime stories connect to the harbour. I’m intrigued by the story involving a figure named Madjuitmadjuit, who was said to dwell in the deep waters and was responsible for regulating the tides of the harbour. I wonder what he would make of it today.

As the catamaran cruises along the shoreline, including past popular Mindil Beach and its throngs of people waiting for the sunset, Darwin Harbour puts on a great show with the constant traffic of navy and freight ships, and cruise liners. There are also fishing boats throwing their nets out to snare prized local barramundi, and passenger ferry services heading out to Mandorah and the Tiwi Islands. Once sunset does arrive, this is where to take a ringside seat for the best show in town, as the colours of the sky shift and day becomes night, while the water moves from a bold tropical blue to a range of dark, moody shades.

All of which is indeed stunning, but for me it’s still what’s beneath where things get really interesting both in the present and in the past.

The deep waters lay testament to the greatest dramas the harbour ever experienced. On February 19, 1942, it became a battlefield when more than 240 Japanese aircraft attacked Darwin, followed by a total of 64 air raids over 18 months. Ships burned, oil tanks exploded, and the harbour was regularly filled with smoke and debris. The destroyer USS Peary sank, where it still lies today as a war grave. It’s not alone there are seven other wartime shipwrecks on the harbour floor, along with debris from downed aircraft, as well as wrecks of craft that sank during the calamity of 1974’s Cyclone Tracy.

Darwin Harbour, just like its city, wears the scars of its past with pride. For all its vast beauty and many tales across thousands of years, it reveals itself as far more than just a picture-perfect waterway ready for another Instagram close-up. With nighttime now covering the city and the cruise coming to an end as the catamaran noses its way back to the dock, I feel I’ve only glimpsed a small insight into the harbour and it’s left me wanting to know much more.