I CAN'T make out a thing in the inky-blue waters beneath me, but I squint into the darkness anyway. A minute later, I see it – an Australian sea lion. A gorgeous coat of silvery grey beaming up from the deep, it flashes its belly as it swerves past me.

A second later, a dolphin follows it in a game of tag, disappearing just as quickly. Then it’s just me again, my heart pounding with awe. I’m on a dolphin swim in the cool waters off Rockingham, a suburb 40 minutes’ drive south of Perth in Western Australia .

This six-hour excursion with Perth Wildlife Encounters costs £157 per person, including lunch and soft drinks, and proves well worth it ( Dolphins.com.au ).

We spotted our first pod of wild dolphins barely five minutes into the trip — but a sea lion popping up is the cherry on top. “This never happens,” Jake, one of the guides, excitedly tells me. “Usually dolphins don’t like to swim with sea lions.

” It’s wildlife experiences like these that keep me returning to Australia. This is my third trip, but my first to Perth, a 17-hour direct flight from London. A popular stop is Rottnest Island — or Wadjemup, as it’s known to the area’s indigenous community of Noongar people — a nature reserve that’s a 25-minute ferry ride off Perth’s coast, with quokkas everywhere.

These cute cat-sized marsupials are famous for the way they “smile” when eating, but you have to lie on the floor to get the perfect shot. While there, I explore on the island’.