Ray Clamback, one of the more experienced ferry pilots (300 US->AU deliveries from memory) went into the drink off Hawaii on two separate occasions and had to tread water for 10 and 6 hours respectively. Nothing "safe" about it.
For example, to ship a new Cirrus SR20 to Australia starts at $28,995 and you'll need to wait for factory reassembly and certification. To ferry the same aircraft costs $22,800.