Cairns and the Great Barrier Reef

Cairns is a friendly little city. compact enouigh to walk around easily.
We did a day trip out to the Great Barrier Reef to go scuba diving with Quicksilver on their boat Quicksmart to The Outer Reef. This was not the cheapest option but as we only had a day to do the trip we though it would be best to go to what people have suggested is one of the best spots, Agincourt Reef.
It was a fantastic day out. We were picked up from our accommodation in Cairns and driven to Port Douglas where the boat left for Agincourt Reef. Luxury snacks, drinks and lunch was included as well as the marine park permit. The boat can take 100 people but there were about 25 snorkellers and 11 divers on our trip so it wasn't too crowded. We payed $229 for 3 dives included all equipment and a guide. One the way back you can go by catamaran back to Cairns from Port Douglas.
Down Under Dive also does other trips and we've heard they are good.
A great website for Great Barrier Reef diving info is Diving Cairns
We also did a trip to Tjapukai, an aboriginal cultural center which was very good. You can take a local bus there and back.