Should Australia invest (in the long run) in a blue water navy?

Other middle powers are developing theirs and it seems we are falling behind, what are they seeing and we are not.

Australia has a Blue Water navy - even our Mine Coastal Hunters leave the Littoral waters and continental shelf of our nation and travel the Pacific. 

The fact that Anzac and Adelaide Class frigates participate in UN Sanctions off Iraq for over 2 decades indicates a blue water capability.

The two big themes in international navies at the movement are:

1) defending territorial claims and protecting commercial shipping through the seasonal openings in the Arctic. e.g. Ice breakers, strengthened hull warships and submarines

2)The second is Littoral Warfare via Littoral Combat type ships to get into the clutter of the littorals and engage brown water and land based targets and avoid sea mines.

Potentially a third is the emerging widespread world wide fleet of hunter killer conventional submarines that use fuel cells or Air Independent Propulsion, are very quiet and are able to sneak up on even the most sophisticated SSN such as USN Virginia and UK Astute. How to detect and destroy them is the issue!