The Whitsundays was my first choice as well. It is a beautiful place with many islands and is protected from ocean swells.
The Nepean runs into the Hawkesbury. The Hawkesbury Classic is a paddle only kayak race that is well established. This from Wiki:
'The Hawkesbury Canoe Classic is an annual marathon canoe race taking place on the Hawkesbury River in Northwest Sydney usually at the end of October. The Hawkesbury Canoe Classic consists of a 111 km paddle downstream starting in Windsor and finishing in Brooklyn. The race is Australia's fourth-longest annual canoe race after the 404 km Murray Marathon, the 208 km Murray 200 on the Murray River between Martins Bend and Morgan in South Australia and the 133 km Avon Descent in Western Australia. The Hawkesbury Canoe Classic has over 600 paddlers each year.
Around 600 paddlers travel 111km in moonlight, down the Hawkesbury River from Windsor to Brooklyn, to raise money for Charity. Over the years the Hawkesbury Classic has developed into a great event. Paddlers, their land crew and hundreds of volunteers converge on the banks of the Hawkesbury River at Windsor on the day of the event to enjoy the fun and competition of an overnight paddle, and the now famous camaraderie and spirit of the event. Paddlers leave Windsor between 4pm and 6pm on Saturday and pass 20 safety checkpoints during the night. The fastest craft arrive at Brooklyn on Sunday morning in less than 10 hours, but the average time is closer to 15 hours'
The problem with extending the race into Broken Bay (mine and Chrisj's stomping ground) and up the coast into Lake Macquarie (Slaughters stomping ground) would mean travelling through National Parks where camping is er.. not permitted. That's one reason why we have contributed to the 'sleeping on board' thread.
I wonder if a major race could get exemptions? There are many fantastic beaches that would be suitable for 'overnighting' on. It's wouldn't really be camping- just sleeping on the beach -(the 'Occupy Sydney group' defense).
The other problem may be big ocean swells and dangerous breaking surf.
Is the EC challenge held on more protected waters?
Maybe the race could finish at Slaughters house!