25 hours from Sydney to London: how to make Qantas's 'marathon' pleasant

Under the distinctive code of QF1, Qantas's daily flagship "kangaroo route" whisks passengers from Sydney to London via Singapore on an Airbus A380. I'm on the upper deck in business class for this marathon journey of 24 hours and 50 minutes (including transit time), departing Monday, arriving Tuesday. Qantas's upcoming Project Sunrise flights seek to trim this to 22 hours non-stop.

CHECKING IN: My voyage is bookended by connections from Melbourne and onwards to Toulouse. Staff efficiently tag my suitcase to France and issue all four boarding passes, including for London-Toulouse on British Airways. Qantas's international business class lounge in Sydney is under renovation. Its temporary replacement is a little busy, but tolerable. Qantas's Singapore lounge is nicer and great for a shower in transit. Cabin baggage allowance is 14kg, plus 40kg in the hold. Higher limits apply for Qantas Club members and elite frequent flyers.

THE FLIGHT: We depart 13 minutes after schedule at 2.58pm, reaching our gate in Singapore at 9.22pm: seven minutes late. The London leg is planned for 11.20pm but we leave at 12.10am, arriving at 7am - 25 minutes late. It's a long flight without Wi-Fi but today's journey is aboard Qantas's very first A380, delivered in 2008, so I let it slide. Fortunately, the cabin has since been upgraded.

THE CLASS: Business class offers 70 seats in a 1-2-1 layout. I'm in 28A to Singapore and 16A to London (window seats). It's comfortable upright, especially with the massager activated, and becomes a two-metre bed with a mattress topper, blanket and large pillow. Two personal air vents make things blissfully cooler, window seats have added side storage, and everybody gets AC plus USB-A power. Four restrooms prove ample and the crew share a trick - closing the curtains by the aircraft doors creates a great changing space (pyjamas are supplied). An inflight lounge gets a workout to Singapore but sits empty overnight to London.

FOOD AND DRINK: This journey has four meal services - dinner plus a refreshment to Singapore; supper and breakfast to London - plus mid-flight snacks to order. Dinner tempts with three starters, four mains and five dessert choices but I sleep straight through the pre-arrival refreshment. Supper offers five main courses with a good variety of proteins: tofu, pork, chicken, beef and fish. The snapper is on point and the chocolate mousse with lemon curd and yuzu crumb is a standout. After almost eight hours of rest, I favour the simple option of Vegemite toast for breakfast, as this aircraft, unlike many others, has a proper toaster.

ENTERTAINMENT: The 16-inch (40cm) HD screen is easy to use and loaded with content including box sets from Paramount+. An old favourite, The Devil Wears Prada, draws me in, then it's onto the latest season of South Park. The A380 also has an external camera - a great background to working on a laptop.