Any remote, region Australians have to learn to become self-sufficient, especially not having the resources of big VMR organisations.
New generation engines are only as good as the maintenance provided to them, low voltage and dirty fuel will stop them as quick as an older rig. Human beings will always neglect toys like boats, seldom used and when used, done so in a very harsh environment.
Most serious recreational ocean passage-makers travel around six knots, so limping home at 4.5 knots is hardly devastating.
Some models have a locking device to stop the engine swivelling, so you can steer from the comfort of the main helm, using the drive as the rudder, as long as the throttle can be locked as well.
long shaft is a must to get prop traction as the boat pitches (fore and aft) in short steep slop. Murphy's Law will generally have a motor fail in rough water.
Having a small separate fuel supply on board is not a big big burden either, people wouldn't mind the inconvenience of the space and weight if it was an esky full of cold cans.
As much as the VMR enjoy the role they play in the community, I'm sure they would rather folks became more self-suffient at sea.