Hi Boiler_81
Lots of great advice I don’t know if it will make it easy or harder
It will come down to the time of year you want to travel and what you want to see.
If diving is the focus, then as advised Mike Ball or the Spirit of Freedom is both great options. They have a mix of itineraries with three, four or combined seven-day trips. As mentioned here already the get out into the more remote regions of the Great Barrier Reef (GBR). However, if you wanted something slightly cheaper and still good diving, the
ProDive option from Cairns is fairly priced with good diving.
Start with the GBR with the time of year you want to go. June – November covers Minke Whale season, coral spawning, clearer water and calmer seas. (Check the operator itineraries for detailed dates). End of November to May, has good diving as well, warmer but wetter (rainy season), and tends to have stronger South Winds due to the Trade Winds. This is also the Cyclone season.
At this time of year, it will also mean the further south you go the colder it is. Maybe start in New Zealand and finish with diving in November? But if you come from a cold area already perhaps warmth is the better option, then start with diving in May finish in New Zealand…
If you don’t mind a drive the East Coast from Cairns to Brisbane (Bryon Bay area as well) is nice. Stop on the way for the Yongala out of Townsville (400kms south of Cairns). Best wreck dive in Australia, and as mentioned should be a stop. Big distance 1600kms though.
Again, lots of choices, bit had to give general advice without what your interests are other than diving. Australia is a land of variety, tropical North or cold South, “wild” West coast of populated East coast. New Zealand rich farming land with culture in the North, South with spaces then Mountain ranges with Fjords…