How are Cruise Ships Becoming More Sustainable

For the cruise industry to achieve genuine sustainability, it’s going to take much more than swapping out colorful plastic straws from cocktails on the lido deck.

Cruise Lines International Association, the trade group that represents most of the industry, has ambitiously pledged to become carbon-neutral by 2050. But how will that look and feel on board?

Here’s a glimpse at several forward-thinking upgrades—a few of which have already been implemented on ships—that will help the cruise industry navigate toward more eco-friendly waters.

1. Sails with solar panels

Illustration of cruise ship sails with solar panels.

Besides retractable sails, plans for Hurtigruten’s Sea Zero vessel includes batteries that can be charged using shore power while in port.

A row of aerodynamic retractable sails covered in solar panels capture the power of both wind and sun at sea. Hurtigruten is relying on such tech for the world’s first zero-emission ship, expected in 2030.

2. No wasted energy

Illustration of cruise passengers in a hot tub.

The amount of heat generated on a cruise ship that could be converted into power varies based on such factors as ship size and engine type.

Heat exchangers collect wasted energy, transforming steam generated by engines into hot water for pools and showers as well as air-conditioning in cabins.

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3. Zero-waste dining

Illustration of cruise passengers with cocktails.

A mai tai made with a syrup crafted from uneaten pastries is served at The Metropolitan Bar on the Norwegian ships Prima and Viva.

In restaurants and bars, zero-waste cocktails are crafted from surplus ingredients. Norwegian Cruise Line’s latest ships, Prima and Viva, already serve such drinks.

4. AI-assistance

Illustration of AI-assisted navigation inside a cruise ship.

Other than increasing navigation efficiency, AI on cruise ships is aiding in food waste management and helping passengers personalize voyages.

AI-assisted navigation analyzes weather data, ocean currents, and other environmental factors to optimize routes and boost fuel efficiency. Royal Caribbean’s Icon of the Seas and Utopia of the Seas already use AI throughout the ships.

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5. Biodigestion

Illustration of a cruise ship chef composting food waste.

By transforming food waste into biofuel, compost, or gray water, carbon emissions are lowered because the processes reduce the need to incinerate or transport to landfills.

In waste systems, biodigesters naturally “eat” food waste by composting and converting biodegradable matter to gray water, which limits harmful greenhouse gases.

6. Greener energy

Illustration of a cruise ship power cable.

Historically, cruise ships have been powered by high-polluting heavy fuel oil. In recent years, biofuels have been tested by cruise lines to serve as viable alternatives.

When a ship is docked, power cables connect to greener energy sources instead of using fuel-guzzling engines. Currently, 35 of the world’s ports are equipped to provide shore power; an additional 39 are funded or planned for construction.

7. Air lubrication systems

Illustration of the bottom of a cruise ship submerged in water.

The use of microscopic bubbles in maritime engineering is an example of biomimicry, where designs inspired by nature lead to innovation.

An air lubrication system generates a curtain of microscopic air bubbles, which help lower fuel consumption by reducing the drag between the hull and seawater.

David Swanson’s writing and photography has been published in National Geographic Traveler, Travel + Leisure, and the Los Angeles Times.