Cruise ships require a lot of resources to operate. An average-size cruise ship uses 1.84 gallons of fuel per second or 6640 gallons per hour. As a result, the industry has taken a lot of heat for its environmental impact. But that is changing as cruise lines work to improve the efficiency of their ships and minimize their effects on marine life. Many modern ships are built with LNG engines with lower emissions than traditional diesel engines. Many use advanced technologies to improve food use, waste management, noise pollution, and wastewater recycling.