We needed a dynamic, low-cost idea to promote the Imax film ‘Sharks 3D’. Effectively a moving ‘floating billboard’, this medium was both affordable and had a high impact on the land-and water traffic in and around Sydney Harbour. High-volume ferry traffic also meant optimal exposure to large numbers of Sydney’s tourist target audience. The real innovation was having the fin towed around the harbour with the rope beneath the surface. This created the startling illusion of a massive shark chasing two men in a small boat.