Accor Hotels are the official partner of the IFDS World Championships with rooms being offered at three locations within an easy distance of Williamstown: the Novotel in St Kilda, the Ibis in central Melbourne, and the Pullman and Mercure hotels in Albert Park.
There's also a range of accommodation options within Williamstown itself, including serviced apartments, bed and breakfast, motels and caravan parks. The Williamstown Information Centre website has a list of the various accommodation choices.