Q: What is the ultimate eco-travel cruise guide for the Yangtze River?

A: There is no single ultimate eco-travel cruise guide, but a system of three non-negotiable mechanical and sanitary rules: zero solids overboard, low-sulfur fuel, and avoiding single-use plastics in the cabin.

The "eco" rating of a Yangtze ship is directly tied to its blackwater holding tank capacity and its pump-out schedule. A ship that claims to be green but has a small holding tank is lying—they are likely overboard dumping at night. Look for newer vessels with vacuum toilets (they use less flush water, reducing waste volume) and engines that burn ultra-low-sulfur diesel, which cuts acid rain over the Three Gorges.

My advice: Carry refillable metal water bottles and a Steripen or chlorine tablets. Refuse all plastic-wrapped soap bars the cabin steward tries to give you. Inspect the toilet base for signs of leaking sewage—if you smell sulfur or methane in the bathroom, that ship is not green, it’s a leaky hazard. Always use the designated shore-side restrooms at dock stops rather than flushing wipes or paper products down the ship’s fragile plumbing system.