A recent issue highlighted in the travel press involved the Caledonia Sky getting into trouble after going aground on the Raja Ampat coral reef. Other cruise-generated mishaps have come about in Alaska, where Royal Caribbean and Celebrity Cruises have settled claims of alleged breaches of the Alaska Marine Visible Emissions Standards over a five year period. Further, according to Jim Walker's Cruise Law News, ".... Alaska issued 18 notice of violation involving 48 instances of excessive air emissions"
Living coral reefs do not escape, either. One cruise company, in order to fit their massive ships into the small port of Falmouth in Jamaica, cleared millions of cubic feet of living coral, pulverized it and then dumped it on an area of old mangrove. The Cayman Islands plan a massive concrete pier in George Town Harbour which, controversially, could cause irrevocable damage to their nearby coral reefs.
Fuel is another bugbear. Cruise ships burn bunker oil which is about the most horrible stuff you can run anything on. There are moves (finally) to use Liquid Natural Gas and fuel cells but still, the main system for propulsion and for provision of on board services has to be diesel in one form or another.
According to Friends of the Earth, cruise ships can produce, in a one week cruise, 10 swimming pools worth of human sewage, another 40 more swimming pools' worth of grey water (that is, stuff like used bath water) and that's before we start to look at the solid waste and what gets pumped out of the funnel. They also mention that the company that is making the greatest strides in controlling pollution is the Disney Cruise Line, who score an A- on the Friends of the Earth cruise ship score card. Disney Cruises have, certainly, be making the most effort to control and limit sea pollution. Those cruise lines that score an "F" on the 2016 score card are Costa, Crystal, MSC and P&O. Cruise ships that score A (the highest cruise ship score... none get an A+!) are the likes of Norwegian Breakaway, Carnival Vista, Regal Princess and the Queen Mary II.
Then there is the matter of humans. The largest cruise ships are the size of a reasonable sized English village - some can carry up to nearly 6,000 guests - with crew on top, then we are looking at about nearly 8,000 souls. This village moves around the small islands of the Caribbean like a plague of locusts, arriving at a port where, say, 5,000 people arrive, get off, wander around and then leave. From the perspective of any given local economy, this means feast or famine. Of course, two or more ships may arrive at the same time, doubling up on those numbers (and, incidentally, on those swimming pools' worth of waste).
The cruise industry needs to follow the path being trodden by Disney; that of trying to make cruise ecologically sound and by also being transparent. Legislators need to start examining the cruise industry much more closely and making sure that sewage and waste is treated on-board and not dumped, that emissions are controlled with particle filters and catalytic converters, that cruise ship anchors stay clear of sensitive marine areas and attention is paid to the economy of local communities where these behemoths stay and disgorge their human cargo.
If you are thinking of booking a cruise, remember that without consumer awareness and legislative control of the damage the cruise industry causes: Where you tread today, someone else, in years to come, may only find a wasteland.