Independent commentary, news and working tools on marine coatings - specifications, fouling control, application practice and the economics underneath. Spec'd in mils. Checked in microns.
Essays, market surveys and field notes for people who spec, buy and manage paint for a living. New pieces every few weeks.
Class approvals are arriving, the autonomy bet is unproven, and the cleaning method has to match the coating chemistry. A field survey of who is actually commercial.
Biocide-free hard coatings reframe the problem: solve for mechanical integrity, groom the rest. What that suddenly lets you optimize for - and the discipline it demands.
A 50 µm roughness penalty compounds to seven figures over a drydock interval - and never shows up as a line item. Three questions to ask before the next spec is signed.
Every underwater hull system starts the same way - blasted steel, anticorrosive epoxy. What goes on top is the strategic decision: deplete it, make it slippery, or make it hard and groom it. Pick one and watch the spec build, coat by coat.
2 × 150 EPOXY · 1 × 75 TIE COAT · 3 × 120 AF - 735 µm DFT
First-order models you can sanity-check a meeting with. Assumptions are printed on the panel. No login, no lead form, no vendor thumb on the scale.
Dial in the fouling rating, vessel class and hull regime. Outputs are first-order estimates from an admiralty-style resistance model and typical SFOC figures - directionally honest, not a class deliverable.
Area, DFT, volume solids, loss factor. The gap between theoretical and practical consumption is where jobs go over budget - so dial in the loss factor honestly, not optimistically.
Northwind - Coastal Charters is a full three-dimensional fleet simulator built in three.js: contracts, drydock scheduling, hull care and the economics of keeping ships on charter instead of idle. It plays in the browser, free, with the same first-order fouling and fuel-penalty logic behind CALC 01 above.
Sign in with a free Mils & Microns membership and your fleet saves to your account, so you can pick up the same ships next time you visit.
Free membership required to save progress. Plays in any browser.
Mils & Microns is written by Adam Stuchlik, a coatings industry lifer with extensive experience through R&D, sales and marketing. The commentary here is grounded in reality, driven by log reports and crawling ballast tanks, not press releases and brochures.
Everything published here is independent. No sponsorships, no affiliate links, no manufacturer slant - if a product is named, it is because the public record supports it.
This site exists because coating decisions are made with too little independent analysis. If you want that analysis on your side of the table, get in touch.
Get in touch →Most coating failures don’t announce themselves.
They show up slowly - as a fuel bill that trends the wrong direction. A drydock interval that arrives six months early. A guarantee dispute that has no clean resolution.
The bad spec doesn’t send a memo. It compounds.
Here’s the math that rarely gets modeled:
A vessel running 50 µm of excess hull roughness above baseline - roughly the gap between a correctly and incorrectly specified antifouling system - carries an estimated 2–4% excess fuel penalty under typical operating conditions. On a vessel burning 50 MT/day of VLSFO at $580/MT, that’s $580–1,160/day above baseline. Over a 60-month drydock interval, the compounding tab can reach $1.1M–2.1M before anyone writes a claim.
No single line item reflects it. It’s distributed. Easy to attribute to weather, route, or load - anything but the coating decision made five years earlier.
The other half of the bill: drydock interval compression. A coating system that underperforms its stated service period doesn’t just cost fuel - it costs you an unplanned drydock event. Depending on vessel class and yard location, that’s $500K–2M+ before the first man-hour is billed.
Three questions worth asking before your next spec:
1. What’s the basis for the service period? Published TDS data, field performance records, or a manufacturer’s projection? These are not interchangeable, and the difference is what ends up in the guarantee clause.
2. Who wrote the spec? If it was the manufacturer’s technical sales team, that’s a proposal - not a specification. Vendor-authored specs are written to maximize performance within warranty terms, not to minimize your TCO.
3. Has anyone modeled the full cost of failure? Not just product price - the fuel penalty curve, the interval sensitivity, and the cost of a dispute if something goes wrong at month 36.
Most operators haven’t run that model. Most specifications are made without it.
That’s the hidden cost of treating coating selection as a procurement decision.
ACM tracks hull performance across the full ecosystem, independent of any manufacturer.
advancedcoatingsmanagement.com
This is a fundamentally different design philosophy. You are not solving for fouling. You are solving for mechanical integrity and then whatever else you want.
Every antifouling on the market is trying to solve the same problem: keep things from growing on your hull. The approach for decades has been chemical - from copper cladding in the past up to modern biocides that target specific critters. It works. It also means your hull is a continuous source of leachates, and whatever else the formulator decided to put in there.
Foul release took a different approach - if I oversimplify it, make the surface too slippery for organisms to stick. Silicone-based systems from Hempel and International dominate that category. They work well on a section of the market but they are soft, damage-prone, can be tricky to apply and cannot tolerate aggressive cleaning. If something does attach and harden, you are in a difficult position.
Pretty much everything in life is a trade-off and in this case the reduction of emissions to air via fuel consumption control has tended to outweigh the emissions to sea.
Another path that I think is the most intellectually interesting one in the coatings space right now: biocide-free hard coatings designed for proactive grooming.
The idea is simple but hard to execute. Instead of focusing on keeping the fouling off through a mastery of chemistry, you apply a hard coating and you clean it regularly before fouling has a chance to establish. Light, frequent grooming through whatever means (watch out for this article) - removes slime and early-stage biofilm while it is still soft and weakly bonded. The coating is engineered to survive this repeated contact without degrading.
This is a fundamentally different design philosophy. You are not solving for fouling. You are solving for mechanical integrity and then whatever else you want. And once you reframe the problem that way, a set of optimization targets opens up that SPC/FRC chemistry cannot touch.
Smoothness. Some of these coatings - particularly the silane/siloxane nano systems - cure to surface roughness profiles under 5 microns. That is glass-smooth. Others, like the glass-flake vinyl ester systems, start considerably rougher out of the gate but reportedly improve with repeated cleaning as the grooming action polishes the surface. There are reports of SPCs self smoothing although I couldn’t find any published studies. Someone independent should run a controlled comparison of FRC and SPC vs hard coatings.
Surface architecture. This is the really exciting one. When the coating does not have to concern itself with certain fouling related properties, the surface itself becomes a design variable. You are no longer constrained by the chemistry of polishing - you can engineer the surface for hydrodynamics.
Think sharkskin. Biomimetic riblet structures that reduce turbulent drag have been studied for decades in aerospace, but conventional antifouling chemistry makes them impractical on a hull - the surface is constantly changing as the coating depletes or fouls. A hard, stable, groomable surface is a different starting point. It holds its geometry. It can be textured at the micro scale and maintained there. GIT's graphene platelet technology is already working in this direction - orienting nanoscale structures to create specific surface energy profiles and flow characteristics that go beyond just "smooth."
The implication is that these coatings are not just passive protection. They are the beginning of engineered hull surfaces - where the coating is designed to hydrodynamically interact with the water, not just survive in it. That is a fundamentally different ambition than anything a biocidal or self-polishing system can offer, because those systems are, by definition, consuming themselves.
Emissions to sea. Near zero or zero. These coatings are inert. No biocides or oils leaching, no microplastic shedding, no copper discharge. Independent lab verification exists for some of the products below. As IMO’s biofouling guidelines tighten and port states move toward stricter discharge regulations - California’s copper limits are already forcing the conversation in the US - this becomes a compliance advantage, not just an environmental talking point. The February 2026 copper re-evaluation bill is a worry for those using it.
VOC emissions to air. High-solids formulations in this category are pushing 95%+ volume solids, which means very low VOC at application. For yards in regions with strict air quality regulations - or for owners who care about Scope 3 reporting - this matters. It also means better coverage per gallon and less waste. And note that I selected volume solids as the metric and not VOC content. The HAPS nonsense in the US is extraordinarily misleading.
Cosmetics. This one sounds trivial until you talk to a cruise operator or a yacht manager. A glossy, hard, cleanable surface stays visually clean between groomings. No streaking, no patchwork erosion, no visible polishing pattern. The hull looks like it was just painted, consistently, for years. For vessels where appearance is part of the brand - and that includes a growing number of commercial operators - this has real value. I remember talking to a container ship owner in the US whose vessels were often idle off the coast of Long Beach. They valued hull appearance very much because their name was plastered all along the topsides in giant letters.
The biocide-free hard coating space is still small enough that you can map the serious commercial players on one hand. Here is what is on the market today, with verified characteristics:
| Product | Manufacturer | Chemistry | DFT | Track Record | Grooming | Differentiator |
|---|---|---|---|---|---|---|
| XGIT-FORCE | GIT Coatings (Canada) | Graphene-reinforced amphiphilic hard foul release (DPET technology) | Single coat over primer (detailed spec not published in public TDS) | XGIT-FUEL predecessor on cruise vessels (Coral Expeditions), propellers on Stolt Tankers (25 vessels), Pacific Basin (40 vessels) | Only biocide-free coating with LR Enhanced Type Approval for grooming (XGIT-FUEL 2024, XGIT-FORCE 2026). Robotic grooming; 1–4 month intervals | Guaranteed 6% out-of-dock power gain vs. premium biocidal AF. Up to 10% fuel savings claimed. Ice/fender impact resistant |
| Ecospeed | Subsea Industries (Belgium) | Glass flake reinforced vinyl ester resin | 2 x 500 µm (1,000 µm total). High initial surface roughness - not a smooth-out-of-dock system | 20+ years in market. RRS Shackleton: coating intact after 12 years in Antarctic ice. Verified non-toxic (independent labs, NL & Canada). 10-year warranty | Proprietary cleaning tools. Manufacturer claims hull smoothness improves with each clean (starts rough, gets smoother - the inverse of most coatings). 10-year drydock interval achievable | Longest track record in category. Ice-rated variant. Life-of-vessel design intent. Extremely abrasion/cavitation resistant. Note: if you ever need to remove it and go in a different direction, blasting off a glass-flake vinyl ester matrix is a serious undertaking. This is a commitment |
| SEA-SPEED V 10 X | Seacoat SCT (USA) | Silane/siloxane nano coating | 2 x 125 µm epoxy + 1 x 150 µm finish coat | 4–12% fuel reduction claimed (manufacturer data). 10-year warranty. No independently verified case studies published to date | Withstands 1,000+ grooming operations without damage. Surface roughness < 5 µm | 95% volume solids, very low VOC. Glass-smooth finish. No heavy metals. Single-coat finish application |
| F2 EcoHull | F2 Eco (EU) | Hybrid polymer with Zeronic™ inorganic resin additive | Multi-coat system (detailed TDS not publicly available) | Primarily yacht/workboat scale to date. 5+ year durability with top-coat refresh (no full rebuild required) | Superhydrophobic surface, ultra-smooth. Fouling removal by light cleaning | Zero PFAS/PTFE. Zero solvents. Compatible with FRP, carbon, aluminum, steel, wood. Emerging technology - watch for commercial vessel scaling |
But let’s not forget, this will not work out so well without a grooming program. A biocide-free hard coating without regular cleaning will foul. You are trading chemical intervention for mechanical maintenance, and if you do not hold up your end, there will be trouble.
This is the single biggest reason the category has not grown faster. It requires operational discipline. It requires either a robotics partner, a reliable diving contractor, or in-house capability for regular hull maintenance. It requires scheduling, tracking, and accountability. For operators who struggle to keep up with basic planned maintenance, adding hull grooming to the rotation is a real ask.
But for operators who can commit to it - and particularly for operators who are already doing regular in-water inspections or cleaning - the numbers shift dramatically. You eliminate biocide complexity and environmental liability. You extend drydock intervals. You maintain out-of-dock smoothness through the entire service period. And you never have to worry about whether your antifouling is compatible with your cleaning method, because the coating was designed to be cleaned from day one.
The regulatory environment is moving in one direction. IMO’s 2023 Biofouling Guidelines and the 2025 in-water cleaning guidance are pushing the industry toward proactive hull management and away from “apply and forget” antifouling models. Port states are tightening discharge limits. Classification societies are beginning to certify grooming compatibility - Lloyd’s Register’s Enhanced Antifouling Type Approval, currently held only by GIT Coatings among biocide-free products, is the first formal recognition that a coating and grooming regime can be validated as a system. It will not be the last. Jotun has already secured a similar approval for their SeaQuantum Skate paired with the HullSkater robot, albeit for a biocidal system - the classification framework is being built in real time.
The biocide-free hard coating market is small - probably in the range of $50 million today, or roughly half a percent of the ~$8 billion global hull coatings market. The broader biocide-free /low biocide category, including foul release and self-polishing systems, is approaching $500 million and projected to more than double by 2035. As robotic grooming technology matures and becomes more accessible, the operational barrier drops. As regulations tighten, the compliance advantage grows. And as more vessels build track records with these systems, the performance data will either validate or challenge the claims being made today.
The elephants in the room are the technical complexity of hard coating + robotics combined with cost. But to achieve near zero efficiency loss, its likely worth looking into.
I do not think biocide-free hard coatings are the right answer for every vessel. They require a level of operational commitment that not every fleet is set up for. But for the operators who are willing to think differently about hull performance - who see the hull as a maintained system rather than a painted surface - this category deserves serious evaluation.
The coatings that do not emit anything (or very little) might be the ones that perform the best. You just have to be willing to take care of them.
I’m tracking the full hull performance ecosystem - coatings, robotics, cleaning systems, and everything in between. Follow along if you want the independent analysis.
Hull cleaning robotics has moved from concept to commercial deployment over the last five years, but the field is fragmented. Six distinct technology approaches now exist, each with a meaningfully different operational model, regulatory posture, and economic argument. There is no winner yet. The question for shipowners is not which robot is best, it is which robot fits the way you actually run your fleet.
This survey covers ten manufacturers chosen for technology diversity, not market share. Jotun's HullSkater anchors the integrated coating-plus-robot model. Shipshave demonstrates that you do not need magnets or autonomy to clean a hull at sea. CLIIN bridges hull and cargo hold cleaning with interchangeable brushes. The Israeli entrant the user could not place is NakAI Robotics, which is taking the most aggressive autonomy bet in the market.
The strongest signal in the last twelve months: Lloyd's Register issued the first full antifouling type approval to Jotun's HSS in 2025, and GIT Coatings approved Armach's EverClean as a hull grooming partner in the same year. Class society and coating-side endorsements are starting to arrive. That matters because class approval is the gating constraint on putting robots into a vessel's planned maintenance system. Without it, robotic cleaning lives in the discretionary spend column.
The cleaning approach drives almost every downstream decision: coating compatibility, port permissions, frequency of intervention, and whether the equipment lives onboard or at the pier. Categorizing manufacturers by tech, not by name, makes the trade-offs visible.
Steel hulls only. Robot adheres via permanent magnets and uses pressurized water (sometimes filtered seawater) to dislodge fouling. Surface vessel typically supports the operation. High throughput (1,000 to 2,000 sq m per hour). Aggressive on coatings if pressure is misapplied. Fleet Cleaner and VertiDrive are representative.
Variable-pressure waterjets, no contact with the hull surface. Designed to preserve coating life. Often paired with debris capture systems to satisfy port environmental requirements. HullWiper and ECOsubsea are the established players. ECOsubsea is the closest to a closed-loop cleaning system, capturing 97% of removed biofouling.
Uses imploding vapor cavities at low water pressure to fracture biofouling without scraping. Marketed as gentler on coatings than mechanical or high-pressure waterjet cleaning. Neptune Robotics is the most commercially deployed at scale, with 60+ Asian ports and 27 robots in operation. CLIIN offers cavitation as an interchangeable head option.
Robot stays on the vessel. Triggered by a remote operations center based on biofouling risk data. Designed for proactive cleaning at the microfouling stage, before macrofouling sets in. Jotun's HullSkater is the flagship and is sold as part of Hull Skating Solutions (HSS), a coating-plus-robot-plus-monitoring bundle. Greensea IQ's EverClean follows the same proactive thesis but as a port-based subscription, not onboard equipment.
Cleans while the ship is steaming. Shipshave's ITCH uses hydrodynamic forces and a tether from a deck winch, no magnets and no autonomy. The crew deploys and recovers it. Cleaning happens at 10 to 13 knots service speed. Reportedly cleans a handysize bulker hull in about five hours en route, removing port-call disruption from the value calculus entirely.
The aspirational category. Robot lives in a docking station on the hull or in a niche, deploys itself on a schedule, cleans, returns to dock, recharges. No tether, no crew involvement after installation. NakAI Robotics in Israel is the most explicit example. Nautica Technologies in Zurich is pursuing a related variant: an autonomous swarm that arrives in port and cleans during the call. Both are pre-commercial or in early commercial trials.
Quick reference across the ten manufacturers covered in this survey. Detailed profiles follow.
| Manufacturer | Country | Technology | Mode | Stage | Best fit |
|---|---|---|---|---|---|
| Jotun HullSkater (HSS) | Norway | Magnetic crawler, rotating cleaning head | Onboard, proactive | Commercial; LR type approval 2025 | Owners committed to a bundled coating+robot system |
| Greensea IQ / Armach (EverClean) | USA | Magnetic crawler, soft brush, proactive grooming | Port-based subscription | Commercial; GIT coating approval 2025 | Operators wanting frequent service without owning hardware |
| NakAI Robotics | Israel | Self-deploying autonomous; UV plus soft brush | Onboard, in-transit, cable-free | Paid trials underway | Owners chasing CII gains with no port stop |
| Shipshave (ITCH) | Norway | Tethered drift cleaner; hydrodynamic attachment, soft brushes | Crew-operated, in-transit | Commercial; multiple fleet deployments | Tankers and bulkers running long voyages |
| CLIIN Robotics | Denmark | Magnetic crawler, interchangeable brush or cavitation heads | Port-based or shipyard | Commercial; cargo hold and hull product lines | Owners with mixed coating types needing flexible heads |
| Fleet Cleaner | Netherlands | Magnetic crawler, high-pressure waterjets, surface vessel support | Port-based, remotely operated | Commercial; 3 service vessels, ROC in Delft | Northern Europe port calls, large vessels |
| HullWiper | UAE / Norway | Brushless variable-pressure waterjet ROV with debris capture | Port-based | Commercial; deployed across 40+ global ports | Owners wanting brushless, coating-friendly cleaning |
| ECOsubsea | Norway / UK | Soft waterjet ROV with 97% biofouling capture | Port-based | Commercial; approved for restricted ports | Vessels in environmentally restricted ports |
| Neptune Robotics | Hong Kong / China | Cavitation waterjet, AI-guided | Port-based | Commercial; 60+ Asian ports | Asia-Pacific trade lanes |
| Hullbot | Australia | Small autonomous magnetic robot, soft brush | Port-based subscription | Commercial; $16M Series A | Smaller commercial vessels and yachts; high-frequency cleaning |
| Nautica Technologies | Switzerland | Autonomous swarm cleaning during port calls | Port-based, autonomous | Pilot stage; $4M seed Jul 2025 | Owners interested in swarm and AI-led autonomy |
Jotun HullSkater (Hull Skating Solutions, HSS) · Norway
Technology Magnetic crawler with rotating cleaning head, multi-camera inspection. Sold as part of an integrated package with SeaQuantum Skate antifouling coating.
Operating mode Onboard permanently. Remote-operated from Jotun operating hubs 24/7. Deployed at harbor or anchor based on biofouling risk modeling.
Commercial status Commercial. Lloyd's Register granted the industry's first full antifouling type approval to HSS in 2025. Deployments include Thoresen Shipping, MSC, HMM newbuilds.
HSS is the only solution on the market that ties coating, robot, and analytics into a single contract. The bet: proactive cleaning at the microfouling stage delivers better fuel performance than any reactive system, and bundling the coating eliminates the warranty argument. The risk: lock-in. You buy Jotun's antifouling whether your spec analysis prefers it or not. The LR type approval is a real moat for now.
Source: Jotun HSS overview, Lloyd's Register press release April 2025
Greensea IQ / Armach Robotics (EverClean) · USA
Technology Autonomous proactive grooming robot with soft brush head. Frequent low-impact cleaning to prevent biofouling at the slime stage.
Operating mode Port-based subscription. Robots deploy from service infrastructure, not from the vessel.
Commercial status Commercial. Subscription service launched 2023. Approved as hull grooming provider for GIT Coatings in April 2025. New San Diego facility opened September 2025.
EverClean is the most direct US challenger to HSS, but with a different ownership model. Owners pay per visit, do not own hardware, and the operator absorbs the equipment risk. The 2025 GIT Coatings partnership matters: it gives EverClean coating-side legitimacy that competitors mostly lack. The recently announced integration with Ocean Power Technologies' unmanned surface vessel platform points toward a fully autonomous port servicing model.
Source: Greensea IQ news releases, GIT Coatings partnership announcement, CMA Shipping 2025
NakAI Robotics · Israel
Technology Fully autonomous, cable-free robot with onboard docking station. Combines UV and soft brushes to clear slime before it becomes macrofouling.
Operating mode Self-deploys from the ship's side while in transit. No crew action required after installation. AI and machine learning adapt to sea conditions.
Commercial status Early commercial. Unpaid POC trials in pipeline, first paid trials negotiated. Funded approximately $3M to date.
NakAI is the boldest autonomy thesis in the market. Onboard, no tether, no crew, no port stop. If it works at scale, it changes the economics of hull cleaning by eliminating service-call coordination entirely. Two open questions remain: how the robot handles real-world sea states across a full fleet rotation, and whether the UV plus soft brush approach can keep up with biofouling pressure in warm-water trade lanes. Worth watching closely over the next 18 months as paid trials report results.
Source: NakAI Robotics company website, Maritime Executive Feb 2025 feature
Nautica Technologies (HYDRA) · Switzerland
Technology Autonomous swarm of small robots coordinated by an AI platform (OceanMind). Robots clean collaboratively without GPS or manual control.
Operating mode Deployed during routine port calls, autonomous operation. Pre-commercial.
Commercial status Early commercial. $4M seed round led by b2venture closed July 2025. Top 100 Swiss Startups 2025 listing. Live vessel tests and pilot projects underway.
Nautica is betting that swarm robotics solves the throughput problem that single-robot solutions face on large vessels. If five robots can clean a VLCC hull during a normal port call, the value calculus shifts. Still early. Pilot results from 2026 will tell whether the swarm coordination overhead is worth the throughput gain.
Source: Tech.eu coverage July 2025, EU-Startups, Vestbee
Shipshave (ITCH) · Norway
Technology Tethered semi-autonomous robot. Uses hydrodynamic principles to attach (no magnets) and harvests propulsion energy. Soft brushes with controlled brush force. Interchangeable cleaning heads for microfouling or macrofouling.
Operating mode Crew-operated from forecastle winch. Vessel speed 10 to 13 knots during cleaning. Two winch types available, including pneumatic for explosive cargoes.
Commercial status Commercial. Multiple fleet deployments. Cleans a handysize hull in approximately 5 hours en route.
Shipshave is the most operationally pragmatic in-transit solution. No magnets means it works on aluminum, composite, or coated hulls that defeat magnetic systems. No autonomy means the crew can interrupt or recover the unit if conditions change. The 50 kg unit comes in two parts crew members can carry. The trade-off is that it is not always-on. It requires crew involvement and a planned cleaning window. For tanker and bulker operators with long voyage legs, that is rarely a problem.
Source: Shipshave company website, ITCH user manual rev 4.0, Ship Technology Global Issue 81
Fleet Cleaner · Netherlands
Technology Magnetic crawler with high-pressure waterjet (filtered seawater). Operates underwater and above the waterline. Flexible multi-axis cleaning heads. Fouling collected via umbilical for filtration and shore disposal.
Operating mode Port-based, deployed from dedicated service vessels (Thunderbird series). Remotely controlled from operations center in Delft.
Commercial status Commercial. Three service vessels in fleet. Capacity ~150 ships per year. Rotterdam Port Fund holds a stake. Cleaning rate up to 2,000 sq m per hour.
Fleet Cleaner is the European reference for the ROV-from-mothership model. Remote operations from Delft is the operational distinction. The Rotterdam Port Fund investment is a signal that this approach has buy-in from one of the world's busiest ports. The umbilical and surface vessel make this a port-only proposition; vessels need to plan around availability.
Source: Riviera Maritime Media, SWZ Maritime, First Dutch portfolio
VertiDrive · Netherlands
Technology Magnetic crawler with interchangeable applications: high-pressure washing, hydroblasting (UHP), abrasive blasting. Designed for dry-dock and steel structure cleaning.
Operating mode Operator-controlled from safe distance via remote control. Primarily dry-dock applications.
Commercial status Commercial. Multiple model lines (V700 series and others). Distributed globally through partners including BlastOne and Joe Johnson Equipment.
VertiDrive sits at the boundary between underwater hull cleaning and shipyard surface preparation. Their use case is mostly dry-dock blasting and washing for steel surface prep before recoat. Worth tracking for shipyard work and as a reminder that not all hull robotics is underwater; the surface prep automation case is its own market.
Source: VertiDrive product pages, BlastOne distributor catalog
HullWiper · UAE / Norway
Technology Brushless variable-pressure waterjet ROV (seawater). No mechanical contact with the hull surface. Onboard biofouling residue collection with shore-side disposal.
Operating mode Port-based, remotely operated. Cleans up to 5x faster than diver-based brush cleaning. 1,000 to 2,000 sq m per hour. Hull cleanable in 12 to 24 hours.
Commercial status Commercial. Available in 40+ ports globally.
HullWiper's coating preservation argument is the cleanest in the brushless category. Variable-pressure jets and no scraping mean no abrasion on antifouling layers. The integrated debris capture satisfies most port environmental rules. The constraint is the same as every port-based system: you only clean when you have a port call, and you compete for service slots with the rest of the harbor.
Source: HullWiper company website, NauticExpo product listing
ECOsubsea · Norway / UK
Technology Soft waterjet ROV with multi-layered filtration and treatment system. Removes 97% of fouling and pumps it ashore through filtration plant; debris reused in biogas production.
Operating mode Port-based ROV. 300 to 600 sq m per hour cleaning rate depending on vessel size and fouling condition.
Commercial status Commercial. Approved for environmentally restricted Norwegian and UK ports including Southampton and Bergen. Approximately 500 vessel cleanings completed at last public update.
ECOsubsea is the closest the market has to a closed-loop biofouling solution. Where most ROV systems claim debris capture, ECOsubsea quantifies it and has demonstrated reuse. This is the manufacturer to recommend when a vessel calls at a port with strict effluent restrictions. The trade-off is lower throughput than HullWiper or Fleet Cleaner; the system prioritizes capture over speed.
Source: ECOsubsea company website, Tank News International, Norwep
Neptune Robotics · Hong Kong / China
Technology Cavitation waterjet (high-velocity microdrops) with AI-guided self-steering. Sonar enables operation in muddy water. Operates above and below the waterline.
Operating mode Port-based ROV. Available at vessels berthed during cargo operations. 24/7 operation including night work.
Commercial status Commercial. 27 robots in operation, 60+ ports across China and Hong Kong including Singapore, Shanghai, Ningbo, Zhoushan, Qingdao, Tianjin, Guangzhou.
Neptune is the regional anchor for cavitation cleaning in Asia-Pacific. The combination of AI navigation and muddy-water operation (via sonar) addresses a real constraint at Chinese river ports where divers and visual ROV systems struggle. For vessels in Asia trade lanes, Neptune is the most commercially mature option. Less relevant outside the Asia-Pacific operating footprint.
Source: Neptune Robotics company website, Maritime Executive coverage, HAX/SOSV portfolio
CLIIN Robotics · Denmark
Technology Magnetic crawler, 89 kg, with interchangeable brush or cavitation heads (35 kg hull tool). Cleans 200 to 400 sq m per hour. Hull and cargo hold robot lines from the same platform.
Operating mode Port-based or shipyard. Fresh water only. Designed for use across coating types and fouling levels.
Commercial status Commercial. Cargo hold cleaning robot is the established product line; hull antifouling line introduced more recently.
CLIIN's positioning is range, not specialization. The same magnetic chassis serves cargo hold and hull cleaning. Interchangeable heads let an operator match the cleaning method to the coating and fouling condition rather than running one tool against every problem. Throughput is below the high-pressure crawlers, but coating preservation is the trade-off. For owners with mixed coating types across a fleet, that flexibility matters.
Source: CLIIN Robotics company website, Maritime Executive coverage
Hullbot · Australia
Technology Small (~10 kg) autonomous underwater robot. Gentle brushes, 4K cameras, sensor suite for inspection. Generates 3D hull models for damage detection.
Operating mode High-frequency subscription cleaning, sometimes multiple times per week. Day or night operation, no schedule disruption.
Commercial status Commercial. $16M Series A 2024. Expanding globally.
Hullbot operates at the small end of commercial. The thesis: do not let biofouling start. Clean often enough and gently enough that nothing accumulates. Reported fuel savings of 12 to 20% on smaller commercial vessels. This is the model to watch as the technology scales to larger vessels. The economics shift entirely when cleaning becomes a routine high-frequency service rather than an episodic intervention.
Source: Hullbot company website, Marine Business News Nov 2023, Series A coverage
Three observations worth flagging before this gets translated into an owner-facing article.
Lloyd's Register's full antifouling type approval for Jotun HSS in 2025 is the most consequential market event in this space. It moves robotic cleaning from a discretionary cost-saving tool to a class-recognized component of a hull performance system. Expect ABS, DNV, BV, and ClassNK to follow with comparable approval frameworks over the next 24 months. Manufacturers without a class approval pathway will struggle to win planned-maintenance budget.
NakAI, Nautica, and the long-term direction of Armach all rely on full autonomy. The promise is compelling: no port stop, no crew action, no service vessel. The risk is that autonomy in seawater is materially harder than autonomy on land, and the operating envelope for in-transit robots is narrower than the marketing suggests. The next 18 months of paid trial data will tell whether the autonomy thesis holds or whether tethered and port-based systems retain the bulk of the addressable market.
A non-trivial portion of vendor disputes in the next five years will hinge on whether the robot damaged the antifouling. High-pressure waterjet against a soft self-polishing copolymer is a different conversation than a cavitation jet against a hard foul release. Owners specifying both coating and robot should require coating-side approval of the cleaning method. The GIT Coatings approval of Armach EverClean and Jotun's bundling of HullSkater with SeaQuantum Skate are early templates for how this should work. Most owner-vendor combinations are not yet this aligned.
All manufacturer claims in this survey are taken from public manufacturer disclosures, press releases, class society announcements, and trade press coverage. Verify against the most recent TDS or technical data when applying to a specific specification.
Jotun Hull Skating Solutions overview and resources, jotun.com
Lloyd's Register press release: First full antifouling type approval for Jotun HSS, lr.org, April 2025
Greensea IQ news releases on EverClean and Armach, greenseaiq.com
Shipshave ITCH product page and user manual, shipshave.no
CLIIN Robotics product specifications, cliin.dk
Fleet Cleaner remote operations center launch, Riviera Maritime Media and SWZ Maritime
HullWiper brochure and capability statements, hullwiper.co
ECOsubsea sustainable cleaning operations, ecosubsea.com and Tank News International
Neptune Robotics service area and technology, neptune-robotics.com and Maritime Executive
Hullbot Series A funding and service model, hullbot.com and Marine Business News
NakAI Robotics company profile and Maritime Executive February 2025 feature
Nautica Technologies seed funding coverage, Tech.eu and EU-Startups July 2025
VertiDrive and Subsea Industries dry-dock and underwater equipment catalogs
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