By Capt. Neeraj Bharti, Founder, Master Mariner · Published · 2 min read
Diver brush carts, cavitation, water jet or ROV: comparing in-water cleaning methods
There is no single best way to clean a hull in the water. Each method has strengths, and the right choice depends on the fouling, the coating, the port and whether debris must be captured. Here is an honest comparison.
The main methods
| Method | How it works | Best for | Watch out for |
|---|---|---|---|
| Diver brush cart | Diver-operated cart with rotating brushes on large flat areas | Flat bottom and vertical sides, a wide range of fouling | Brush choice must match coating; capture needs an adapted system |
| Diver hand cleaning | Hand tools and scrapers | Niche areas, edges, heavy growth in small areas | Slow over large areas |
| Water jet | High-pressure water directed at the surface | Some fouling types; non-contact | Can damage soft coatings at close range |
| Cavitation | Collapsing bubbles remove growth without brushing | Growth removal with less mechanical contact | Specialist equipment; availability varies |
| ROV / robotic systems | Remotely operated crawlers, often with capture | Large flat areas; capture; less diver time | Niche areas, curvature and heavy growth are harder |
How to choose
Fouling level. Slime suits gentle, proactive cleaning. Heavy barnacles need more force and usually capture.
Coating. Foul-release coatings need the gentlest methods. Hard coatings tolerate more.
Areas. Brush carts and ROVs are efficient on large flat areas; niche areas almost always need divers and hand tools.
Capture. If the port requires capture, the method must include a capture system approved or accepted there.
Port acceptance. Some ports permit only certain methods or approved companies.
Conditions. Visibility, current and swell affect divers and robots differently.
Our method
Cleanship's underwater hull cleaning uses diver-operated brush carts on the flat bottom and vertical sides and hand cleaning on niche areas, with brush selection matched to the coating and debris capture where the port requires it. We tell you at quoting stage how we will clean your hull and why. See our underwater hull cleaning service.
Related reading: capture or no capture, how cleaning damages coatings, and the complete guide to ship hull cleaning.
Sources & further reading
Frequently asked questions
What is the best method for in-water hull cleaning?
There is no single best method. Brush carts suit large areas, hand cleaning suits niche areas, and water jet, cavitation and ROV systems each have uses. The fouling, coating, capture requirement and port rules decide.
Are robots better than divers for hull cleaning?
Robotic systems can be efficient on large flat areas and often include capture, but niche areas, curvature and heavy growth still usually need divers.
Which cleaning method is safest for foul-release coatings?
The gentlest method that removes the fouling, with soft tools and few passes. Hard brushes and close-range high pressure can scratch silicone foul-release coatings.
Does the method affect whether a port allows cleaning?
Yes. Some ports require capture or only accept certain methods or approved companies.
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