What happens when you strap 4 x 350hp v8 engines 1400hp to the back of a custom built boat and let it loose on the most beautiful harbour in the world the result is harbour blast sydneys fastest aquatic adventure departing from circular quay thrill seekers will experience an unforgettable 60 minute lap of sydney harbour twisting and turning along the shoreline passing sydneys most iconic and spectacular landmarks and vistas reaching speeds over 90 kilometers per hour photo opport