As far as the south coast of Australia goes, just don't go there. Sail past it and turrn north when you don't see it any more. Drive down there from Sydney and have a look from the top. ( at low tide, that is an awesome photo)
Speed, I still use a chip log my Grandfather built. Thorw it off the stearn and count.
Direction, well the sun comes up and goes down and if the stars are out Pleadease (sp) alway's points east. ( I use this all the time because my compass
light is still broke.)
Thor Hyeredahl. Who here has besides me worked for him. I know his niece and dated her Daughter as well. He was a freak'n genius. And he broke the mold on isolation vs. transmigration through observation and proof through re-enactment voyages.
The argument here is more about not having a foundation in the art/science
of basic simple deductive reasoning. Using what you have available in nature, coupled with some simple and non-problamatic instruments, like a compass
and an Timex. Not needing 10,000 people to get up and go to work keeping the interactive systems in check just so you can know where you are.