Air lubrication systems pump air under a ship's flat bottom to cut frictional resistance, and Silverstream alone reports more than 250 orders and over 150 ships running. Vendors claim 5-12% net savings, but the Shell trial and Grimaldi's fleet data point to a realistic 3-7% net on full-form hulls.
What it is and how it works
An air lubrication system injects air through units in the hull bottom to form a carpet of microbubbles or a thin air layer under the flat of bottom, reducing frictional resistance. The air comes from dedicated compressors in most systems, from blowers in the Mitsubishi design, from the main engine's turbocharger and scavenge air in the engine-supported variant that Silverstream is testing with Everllence, or from a passive venturi driven by the ship's own motion in Armada Technologies' PALS. The net saving is the gross drag reduction minus the power spent compressing air, which is why full-form, flat-bottomed ships such as cruise ships, LNG carriers, ro-pax vessels and large container ships are the main adopters, and why net figures sit well below gross claims.
Why it matters now
A saving of a few percent compounds on fuel-hungry, high-value tonnage exposed to CII ratings, the EU Emissions Trading System and FuelEU Maritime, and orders since 2025 have been newbuild-led in cruise, LNG carriers and ro-pax. Clarksons Research counts air lubrication among energy-saving technologies fitted on 14,189 ships, 46.1% of fleet tonnage, at the end of 2025 (Cyprus Shipping News). It is also the most widely adopted of the exotic hull options: Lloyd's Register reported more than 100 Silverstream systems in operation in July 2025, and Splash247 later reported 164 vessels running and a company estimate that its customers will save almost USD 5 billion in fuel over system lifetimes.
Key players and products
Silverstream Technologies passed 200 orders with an 18-ship LNG carrier deal (Silverstream) and, when Carnival Corporation extended its partnership in August 2026, its chief executive cited more than 250 orders and over 150 installations (Seatrade Cruise). Mitsubishi Heavy Industries first applied MALS to cruise ships on two AIDA newbuilds delivered in 2015-16, expecting around 7% fuel reduction, after a ferry trial confirmed more than 5% energy saving. Alfa Laval took full ownership of Marine Performance Systems in March 2023 and claims real-world savings of 12% for its fluidic OceanGlide bands, with first retrofits on an Odfjell chemical tanker and a Kumiai Navigation LPG carrier. Armada Technologies signed with TUI Cruises to fit its passive system on Mein Schiff 6 in 2027. A vendor landscape summary by ShipUniverse gives a net range of 3-8% for retrofits.
Figures that matter
| Metric | Value | Source type | Source |
|---|---|---|---|
| Silverstream claimed net saving | 5-10% | vendor | Silverstream |
| Shell/Silverstream trial, November 2025 | 4.3% ballast, 3.8% laden | trade-press | Digital Ship |
| Grimaldi net saving on some vessels | 5-6% | trade-press | — |
| Silverstream orders and installations, August 2026 | more than 250 orders, over 150 installations | vendor | Seatrade Cruise |
| MHI ferry trial | more than 5% | vendor | MHI |
| Alfa Laval OceanGlide claim | 12% | vendor | — |
| Net range for retrofits | 3-8% | aggregator | ShipUniverse |
Silverstream claims 5-10% net savings depending on vessel type and operating profile. The Shell trial reported in November 2025 recorded 4.3% in ballast and 3.8% laden, with the partners arguing that an optimised system could reach 5% on a full-bodied vessel, and Grimaldi has achieved 5-6% net on some vessels (Digital Ship). Alfa Laval's 12% claim has no independent verification in this research, and no cost or payback data for air lubrication units were found. Silverstream's 2022 target of 500 sales by 2025 was not met on the figures above.
Developments 2023-2026
- 2023: Alfa Laval takes full ownership of Marine Performance Systems and announces the Odfjell chemical tanker retrofit of OceanGlide.
- 2025: Lloyd's Register reports more than 100 Silverstream systems in operation in July; the Shell trial result is reported in November; Grimaldi selects Silverstream for nine ro-pax newbuilds in December, bringing its group total to 35 ships (MarineLink); Finnlines orders the system for two ro-pax newbuilds.
- 2026: Silverstream and Everllence complete one year of in-service testing of an engine-supported system fed from the main engine's air system rather than separate compressors (Silverstream); Carnival extends its partnership in August to Carnival Cruise Line's Ace-class newbuilds at Fincantieri, with the first delivery in summer 2029 and more than 127,000 running hours already logged across the Carnival fleet.
- 2027 scheduled: Armada Technologies installs its passive system on TUI Cruises' Mein Schiff 6.
Outlook
Adoption will stay newbuild-led in cruise, LNG carrier and ro-pax tonnage, with Silverstream's Ace-class deliveries running to 2033. The engine-supported variant could reduce the compressor power penalty that limits net results. For planning, 4-6% net on a full-form hull is defensible; 10-12% figures remain unverified vendor claims, and no 2025-26 installation count for MALS surfaced in this research.
