What are Some Ways That Boats - Especially Cruise Ships - Be Environmentally Friendly?

Question

Besides that, what do Cruise Ships do about carrying fresh water with them? What do they do with food scrapes and sewage? What are Cruise Ships usually made out of?

Answer 1

Some vessels have gone to a low emission engines.   The newer outboards are now 4 cycle engines, no mixing oil in the gas, no excess oil fumes or deposits in the water.

Cruise ships run on diesel fuel or a type of diesel.   The cruise ships make their own fresh water from sea water.   All sewage is treated and processed before being pumped out.  

Garbage is ground and also dumped overboard, but can not be close to shorelines.

Most all modern cruise ships are metal - steel hulls.  New requirements regulated the type of paint that can be used on the hull as well.  Some ports will not let a vessel dock if they do not have proof of the type of paints used on the hull.

The biggest problem is ballast tanks and commercial vessels that dump ballast water over board.  Ballast water may have oil and other contaminates in it.

Answer 2

There is nothing environmentally friendly about ships or boats.

Nothing.

Answer 3

The best way to make them environmentally friendly would be to haul them out of the water - and that wouldn't even be foolproof.  They usually have desalination plants aboard, so they distill sea water and make it fresh.  They have facilities onboard that hold kitchen waste and wastewater, and it is disposed of when the ship reaches port.