There are plenty of places here for SCUBA diving whether you are a complete beginner and wish to try diving, or a certified diver.
Places to dive are Wavebreak Island, The Seaway, South West Wall, South Wall and North Wall. Plenty of parking, but entry to the Seaway here may be difficult for some. Need a post dive snack or drink? Then try the cafe located about 50 metres from the entry and close to the seaway tower.
There is also off shore the Scottish prince. A rather old and broken up wreck but still nice to dive. Also located further up north is the artificial reef The Ex-HMAS Brisbane which lies in about 27-28 meters. This is a great dive for any level Open Water upward, as the forward decks lie at around 12-15 meters.
If you are planning on diving around the Gold Coast here at Surfers, I recommend Devocean Dive on Scarborough Street. http://www.devoceandive.com/
The staff Pete and Shona and Pete's son Tony are a great laugh and really nice people. Oh and you might be lucky to get fussed big time by the guard dog. ;) Lol!
They have great local knowledge and experience, and I would say it is vital for a DLD orientation for divers of ANY level and experience, as the currents around the seaway can be quite strong at times. These guys also arrange trips to the beautiful byron Bay weekly and Cook Island dives. I'm sure if you spoke to them prior to your arrival, they would be able to arrange other trips or point you in the right direction. Equipment hire is on offer as well as getting yourself a fill of breeze. There also have a nice selection of diving gear on offer.
A huge variety of marine life can found here. I have seen stripeys, morwongs, trevellay, shovel nose sharks, bull rays, eagle rays, a turtle, morays e.t.c, and I had the privilege of encountering a manta with my buddy last year. I have also had a picture I took of a shark printed in the local paper.
You might also want to try and check out Ian Banks at Dive the Gold Coast. A well known local figure, famous I guess for his local diving knowledge, photography and videography.
Go to his website and contact him via phone or e-mail. http://www.divingthegoldcoast.com.au/
For Japanese tourists, I recommend you try SPD, Surfers Paradise Divers, which is run by Japanese. http://www.spd-au.com/ You can bring you own gear, or you are able to hire from a few places such as Devocean.