Adelaide is where plenty of military marine action is at, or not, depending on contracts and the cycle of the military white paper budget planing.
I've worked in the marine engineering business (military and civilian) for a long time, and it's either boring as bat shit, or working on a cool project when the budget is fresh.
But the cool projects are rare, so it's going to be 90%+ boredom guaranteed. Yep, it's all paperwork, and wait five weeks for coax part J101-K20-C1 to complete your trivial task.
The trick is to only get in on the new development projects from the beginning, then once it hits the trial phase, run like hell!
Never ever join a "refit" project.
Biomed is mostly big in traditional spots like Sydney and Melbourne, lots of companies around. They are pretty anal places to work for. Half my former colleagues ended up at biomed companies, and the ones that were happy to trade boredom for cushy are still there.
For marine it won't matter what degree you get given your past experience, but biomed are more picky. The trick to getting into Biomed is to not be too dumb, and not bee too smart, you have to be just right and tick all their silly HR boxes.
Dave.