Diving in Queensland with Brisbane and Cairns

Be sure to ask at a tour desk or tourist office before you book a diving tour. Tours vary in size and some specifically cater to certain people; if you're an experienced diver, for example, you won't want to be stuck on a daylong introductory dive trip with aquaphobic tourists. If you're a relatively new diver, on the other hand, you'll need to make sure to visit a dive site that doesn't require advanced skills, and where plenty of qualified, certified staff will be on hand to assist you if necessary.

Deep Sea Divers Den (319 Draper St., CBD. 1800/612223. www.diversden.com.au) has a roaming permit that allows guides to go to any part of the reef, including 17 private moorings. The company organizes day trips on one of two boats that include two or three dives, gear, and lunch; and multi-day live-aboard trips. From A$90 for a two-dive day trip.

American Mike Ball Dive Expeditions (143 Lake St., CBD. 07/4031-5484 or 1800/643216. www.mikeball.com) has been diving the Great Barrier Reef since 1969 and is credited with many underwater "firsts." Ball runs multi-day, multi-dive trips along the Queensland coastline on which experienced divers get to set their own bottom times and dive their own plans—or be expertly guided. Custom-built, twin-hulled live-aboard boats bristling with top-end gear, serious divers, and qualified chefs depart Mondays and Thursdays—prices are all-inclusive. From A$1,300 for a three-night, 12-dive trip.

Pro Dive Cairns (116 Spence St., CBD. 07/4031-5255. www.prodivecairns.com.au) conducts two-night trips to the Great Barrier Reef as well as night dives for all skill levels.

Quicksilver (Great Adventures office, Marlin Marinathe Esplanade, CBD. 07/4031-4299) is the best one-stop shop for getting out to the reef, especially if you're a beginner. Excellent, personable staff run sightseeing, snorkeling, and diving tours on sleek high-speed catamarans to activity platforms at Agincourt Reef on the outer Great Barrier Reef for A$186 per person, with optional Sea Walker helmeted seabed walks (A$134) and scuba diving (A$99-A$134). The underwater observatory here lets you get a close-up view of the fish. Quicksilver also takes small-group sailing tours to the Low Isles coral cay with a marine biologist (A$132) and scenic helicopter flights (from A$125). A$5 reef tax is levied on all passengers. Tours depart daily from Cairns, Palm Cove, and Port Douglas.

Tusa Dive (Shield St. at The Esplanade, CBD. 07/4047-9100. www.tusadive.com) is renowned as being the best day-dive boat. Boats take up to 28 divers, but underwater groups are limited to about 6 (for an extra A$25, get your own underwater guide). The fast, well-equipped boats have roving permits to visit 21 different dive and snorkel sites—generally two per trip. Between dives, watch underwater videos, refuel, and relax on deck. A staff photographer snaps everyone underwater: purchase pics of yourself bonding with that turtle 10 minutes after you surface. A full day trip, including two dives, gear, buffet lunch, and snacks is A$205 (plus a reef tax of A$15). Tusa's Spirit of Freedom luxury live-aboard runs three-, fou-, and seven-day dive trips to Cod Hole and Ribbon reefs or Osprey reef in the Coral Sea (from A$1,190 per person).