https://thewest.com.au/news/regional/dredging-to-keep-port-open-to-cruise-ships-ng-b88624821z..this story talks of the problems in Australia.Imagine the costs of dredging in our sand box! One bunker fueled retrofitted 1990s rust bucket could not fund the never ending effort. I am on a Seabourne N. Europe cruise this month.They need a minimum of 10 meters depth to dock. In the shallow bay of Finland channels are constantly dredged (12 or them) The first mate thought the Northern Sea of Cortez would be a " big problem" . Also the modern ships like the Seabourne Ovation use a clean burning mix while in Port.You can see the difference in smoke from the 2002 build and a newer Viking....picture a 90s ship pumping out black smoke down Sandy Beach..