Hi there. I live and work in Cairns as a dive instructor (since 1991) and have experience with most of the trips there. Also I run a small web booking site that offers discount on the trips there for divers from these forums.
I have also dived both in Fiji (long time ago though) and of course here. I think the main difference is that here the safety standards are extremely high and all operators are monitored. In Fiji it’s a bit hit and miss. You need to do a bit of research into who you could go with their .Also it is still a volatile place politically, so make sure it is safe to travel to the location of your choice.
Lastly here on the Barrier Reef it is a marine park that is protected. Many places in Fiji are still fished, so the marine life is not quite as abundant.
I am obviously a bit biased living and working on the Barrier reef, but also it is not considered one of the natural wonders of the world for nothing!
By the way, in October on the Reef the seas are usually at their calmest with a water temp of around 25 deg C. Sept and Oct are the nicest months to visit as the hot rainy season is a few months away. So its nie and warm, with the seas calm, warm with usually great viz
---------------------------------------------------------------------------------------------
Discount dive travel to the Barrier Reef and Coral Sea - live aboard and day trips.
Cairns Discount Dive Trips - Main page