Pick a beach, any beach.... It's summertime in December and Australians love to head to the beach for Christmas. Just about every town has plenty of fun things to do. Gold Coast is a good suggestion, but in Sydney Bondi Beach has a massive beach party. Byron bay is another hot spot.
As I said it's high season in Australia, accommodation books out months in advance. Tickets to the official beach parties sell out early too. Most local councils ban drinking on the beach, except in official party zones. The partying can get too hard and like anywhere there's someone looking for a fight, so stick with your friends and stay calm.
It's also the time of the greatest danger on the roads (and many of the beach towns are significant distances from the major cities - Byron is 10 hours from Sydney!), so drive carefully. Police will be out in force and the legal drink/driving limit is .05.
Phil about 6 years ago
South of Sydney is a beautiful little beach with white sands and bush heaven - GreenPatch. Its school holidays then so there will be crowds (but that will be everywhere).
http://www.shoalhavenaccess.com.au/sites/greenpatch.htm about 6 years ago
You could try Cairns and Tropical North Queensland. We have some wonderful beaches but without the crowds. Cape TribulationBeach - lots of hikes, horseriding, sea kayaks, jungle surfing, trekking etc. Port Douglas - relaxation relaxation, also Daintree river cruises, fishing, The Great Barrier Reef. Cairns - many northern beaches with great deals on apartments. Reef, rainforest, waterfall, bungy, skydive, skyrail/train, Green & Fitzroy Islands, horse riding, ATV, white water rafting - the list goes on. You definately will not be bored - or you may just relax about 6 years ago