drive across darwin harbour

Short answer: no, you can’t drive across Darwin Harbour—there’s no bridge, unless your 4WD has a snorkel the size of a periscope. If you need to get to the Cox Peninsula by car, you’ll be going the long way round via the Stuart Highway and Cox Peninsula Road, roughly 120–140 km and about 1.5–2 hours depending on traffic and roadworks. There is a passenger ferry from Cullen Bay to Mandorah, but it doesn’t take cars, so the Hilux stays ashore. In the Wet, check NT road reports because low-lying sections can flood faster than you can say “build a bridge.”