At Cruise Express, we love sharing the joy of cruising and we also know how important it is that the industry protects the beautiful destinations we visit. So we’re excited to see the latest 2025 Environmental Technologies & Practices Report from Cruise Lines International Association (CLIA), which shows just how far cruising has come in building a greener future.

With CLIA-member cruise lines representing more than 90% of the global fleet, this report gives a clear snapshot of the real, tangible progress being made.

A Fleet Evolving for Tomorrow

As of 2025, CLIA’s 45 member cruise lines operate 310 oceangoing ships, most of them small to mid-size (under 3,000 lower berths) a trend set to continue well into the 2030s. But what really stands out is the investment: more than 80 new, cleaner, smarter ships are already on order worldwide, each designed with sustainability front and centre.

Cleaner Fuels & Smarter Engines

The shift away from heavy fuel oil is well underway. Cruise lines are trialling and adopting alternatives including biofuels, methanol, and LNG, with incredible progress in multi-fuel engines. Multi fuel engine technology provides the flexibility to switch from conventional fuels to zero and near zero emission fuels with little to no engine modifications. In 2018 there was just one ship with this capability, today there are 19, and by the end of 2025 there will be 23, with 32 dual-fuel ships due to launch before 2036.

These ships can switch to low- and zero-emission fuels as they become available, meaning every new vessel is built with the future in mind.

Plugging In at Port

One of the most exciting developments is onshore shore power supply (OPS) connectivity (also referred to as shoreside electricity or SSE). When ships can plug into electricity in port, they can switch off their engines – reducing emissions by up to 98%.
Today, 166 CLIA-member cruise ships have this capability, and that number is expected to jump to 273 by 2036. Ports are catching up too, with Europe leading the way. Pleasingly, by late 2026, Sydney’s White Bay Cruise Terminal in Balmain will take an important step forward, becoming the first port in Australia and the Southern Hemisphere to offer renewable shore-side power for visiting ships.

Cleaner Air, Cleaner Seas

Ships are also adopting advanced technologies like Selective Catalytic Reduction (SCR) systems that significantly cut particulate matter and nitrogen oxide emissions, helping meet strict global standards.

Meanwhile, nearly all CLIA-member ships (98%) now produce their own fresh water on board using systems like reverse osmosis and steam evaporation – a massive step in reducing reliance on limited local water supplies.

And when it comes to wastewater, more than 80% of the global fleet uses advanced treatment systems that exceed international requirements, with even more progress planned. As part of their overarching sustainability focus, cruise lines have committed to not releasing untreated sewage anywhere in the world during normal operations.

Rethinking Waste Onboard

From waste-to-energy gasification systems, where these systems convert waste into usable energy to support the ship’s operations, reducing waste sent to landfills and decreasing the ships energy demand to Microbial food waste digesters, currently in use on 128 vessels, cruise ships are becoming incredibly efficient. This is an exciting and huge leap forward from even five years ago.

Why This Matters to Us (and Our Travellers)

Sustainability isn’t a trend – it’s essential. At Cruise Express, we’re proud to work with cruise lines that are investing heavily to protect the oceans, wildlife, and communities we visit. It means you can explore the world with confidence, knowing your holiday is part of a cleaner cruising future.

If you’d like to know more about sustainable ships, new technologies or eco-friendly itineraries, we’re always here to help.

Data: Cruise Lines International Association (CLIA) Environmental Technologies and Practices (ETP) report 2025