I would concur with those who say don't stay in Cairns. It's your typical touristy beach town full of drunk college students and "gap year" backpackers. If you have a couple of days, I would recommend the Cairns Dive Center and their "Floating Reef-otel" which offers 3-day, 2-night tours to various points along the reef.

You sleep aboard the boat and spend a day each starting at like 5AM at several spots along the GBR Marine Park. Meals, such as they are, are included as are your dives. They also offer snorkeling and prescription masks. The accomodations are a bit on the budget side though, so if you want high-end accomodations on the high-seas, you might want to check out one of the other liveaboard operators.
http://www.cairnsinfo.com/tour/Scuba%20Dive/121/

I had considered going on the Quicksilver boat, but signed up for the CDC package when I learned that it was a bit more than two trips on the Quicksilver boat(~$250AU) and was definitely much more worth it. My prices go back to 1997 though.

I could not find a web site for them, but did find this link via Google:
http://www.cairnsreefdive.com.au

I got to CNS on the now extinct AN.

JD

[This message has been edited by Jet'Dillo (edited 08-10-2003).]