"Double sunrise" flights in WW11

Ivan Peirce, 70 years ago, flew 44 round trips between Perth and Ceylon (Sri Lanka) in Catalinas during WW11. Each way was 29 hours flying so they were called "The double sunrise". No radio,no lights and using astral navigation. They took turns resting on the fuel tanks when not flying. No hot meals...in fact, awful. Yet, they were a vital link between Australia and Europe and they knew it!