The Rip is one of the most dangerous passageways in the world because this narrow stretch of water opens out into a wide and long bay and the tides and stormy weather create havoc. In the sailing days the entrance to The Rip was hard to find and navigate but it had to be done because Victoria's capital city, Melbourne, was a very important port and it was inside Port Phillip Bay. Numerous shipwrecks litter the south coast of Victoria.
At some stage a channel was blasted through the rocks in The Rip but it only allows ships with a draught of 11.6 m. Large container ships need 14 m to carry full loads to and from the port of Melbourne. So the controversial decision was made to deepen the channel at the heads and further into the bay and the Queen of The Netherlands arrived to do the job.
When we were at the Point Lonsdale lookout today the Queen was working in The Rip. She then moved into the bay a little to allow a container ship through. Apparently the cargo ships have to give 30 minutes notice so the dredge can get out of the way.
Most objectors argue that the turbid plume from the dredge will damage the environment in the bay, and that the dumping of the dredged material (much of which is toxic) in a particular spot in the bay is not secure enough even if it is to be topped with clean sand. The photo below (not mine - I nicked it from the ABC's webpage) shows the plume that follows the dredge.