9 Air Lubrication Claims Owners Should Verify Before Believing the Savings
Air lubrication has moved well beyond concept-stage marketing. Lloyd’s Register said in 2025 that Silverstream’s system was installed on more than 100 vessels and had logged more than a million hours of in-service monitoring, with uptake spreading across cruise ships, LNG carriers, containerships, Ro-Ros, PCTCs and bulkers. At the same time, third-party verification, retrofit planning, and performance measurement remain central because the commercial result depends on more than the headline claim. Owners still need to check net versus gross savings, blower power, hull form suitability, speed profile, draft range, fouling condition, verification methodology, and the actual objective of the retrofit before treating any percentage as bankable. LR explicitly says third-party validation is beneficial rather than relying only on claims, and current ship-performance literature continues to show that weather, fouling, and operational profile materially affect measured efficiency outcomes.
9 air lubrication claims owners should test before underwriting the promised benefit
Air lubrication can absolutely be material on the right ship in the right service. The danger is not that the technology never works. The danger is that owners treat a strong-looking savings number as transferable across hulls, drafts, speeds, weather patterns, maintenance standards, and verification methods that are not actually comparable.
The claims that deserve harder owner-side checking
The aim is not to dismiss air lubrication. It is to separate the most bankable cases from the most easily overstated ones.
The claimed saving is the saving you will actually keep
The first question should always be whether the number is gross drag reduction, gross fuel effect, or true net vessel benefit after the system’s own energy demand is included. Owners need the operational answer, not just the physics answer. The commercial case rests on the number that survives blower or compressor power, control-system demand, and the ship’s actual usage pattern.
The same percentage works across most ship types
That is rarely a safe assumption. Air lubrication tends to fit certain hull geometries and operating profiles better than others. Larger ships with a broad flat-bottom area are often positioned as better candidates, but that still does not make every large ship a strong case. Owners should test whether the vessel’s hull form, draft pattern, trim behavior, and route profile match the conditions under which the claim was achieved.
The trial result equals the in-service result
Sea-trial and demonstration outcomes are not meaningless, but they are not the same thing as long-run commercial performance. In service, the vessel sees weather variation, loading differences, fouling, schedule pressure, maintenance interruptions, crew-operation variability, and different speed bands. Owners should be much more interested in monitored service data over meaningful periods than in isolated best-case runs.
The system performs the same across wide speed and draft ranges
Many efficiency technologies are speed-sensitive, and air lubrication is no exception. A ship that spends much of its life outside the most favorable band may not realize the same value as a ship with steadier operating conditions. Draft and trim variation can also influence how effectively the air layer is created and maintained beneath the hull.
Hull condition does not change the commercial answer much
Hull and propeller condition materially influence ship performance, so owners should be careful about any energy-saving claim that seems detached from fouling condition and maintenance state. A vessel with deteriorating hull condition is already moving against a shifting baseline. That makes it harder to isolate what portion of the outcome belongs to the air lubrication system and what portion belongs to hull degradation or maintenance timing.
The verification method is obvious and neutral
Verification sounds straightforward until owners ask how the baseline was chosen, what data was excluded, whether the comparison periods were symmetrical, how weather and current were normalized, and whether the result was independently reviewed. Strong claims deserve strong methodology. Weak methodology can turn a technically plausible result into a financially misleading one.
Retrofit complexity will not materially change the economics
Owners should not judge the system only by operating savings. Retrofit planning can involve structural checks, electrical work, piping, equipment placement, drydock coordination, and ship-specific engineering that affect both capex and off-hire risk. Even a good technology can produce a weaker return if retrofit complexity is treated like a footnote rather than part of the investment case.
The same result survives different commercial objectives
Owners need to be clear about whether they want lower fuel at the same speed, higher speed at the same fuel, better carbon metrics, or more schedule flexibility. Those are not identical targets. The measured result can look attractive under one objective and less compelling under another. Good owner-side diligence starts by pinning the savings claim to one commercial aim.
Third-party validation is optional once the vendor history looks strong
Owners should resist that shortcut. Even when a supplier has a meaningful installed base, third-party validation still matters because ship performance evidence can be framed in more than one way. Independent review helps test whether the claimed benefit is real, transferable, and measured in a way that fits owner economics rather than marketing language.
A faster owner-side filter before the sales case hardens
This table turns the common claims into a shorter diligence map owners can use in early screening.
Air lubrication diligence map
A practical look at the claim, the hidden variable, and the question owners should ask first.
| Claim area | Hidden variable | Why it changes the answer | Best first owner question |
|---|---|---|---|
| Savings percentage | Gross versus net treatment | System power demand can materially reduce the bankable number | Is this after blower or compressor power is counted |
| Ship-type fit | Hull geometry and bottom area | Not every large hull benefits equally | Which sister or near-sister cases are you comparing us to |
| In-service performance | Weather, current, speed, and loading noise | Best-case runs may not survive daily trading conditions | How was the service data normalized |
| Speed benefit | Operating band sensitivity | Value may weaken outside favorable speed ranges | Show the savings by speed band not one average |
| Hull condition | Fouling and baseline drift | Performance can move for reasons unrelated to ALS | How did you isolate hull degradation effects |
| Verification quality | Baseline choice and data exclusions | Weak methods can flatter the result | Who reviewed the methodology independently |
| Retrofit economics | Installation complexity and off-hire | Capex and schedule impact may soften the return | What is the full installed and off-hire case not just the operating case |
| Commercial objective | Fuel, speed, carbon, or schedule priority | The same system can look different under different goals | What exact business target is the claim built around |
| Vendor credibility | Need for third-party confirmation | Experience helps but does not replace neutral validation | What evidence has been independently verified |
Air Lubrication Claim Credibility Check
Use this to estimate how hard an owner should challenge a savings claim before treating it as investment-grade. It is not a hydrodynamic model. It is a commercial diligence aid.