A boat being lifted out of the water, its hull bottom and propeller showing

Ships

Making ship propellers harder for barnacles and algae to grip.

We hold back the barnacles and algae that grow on a ship’s underwater parts by working on the material’s surface. On a brass propeller, a 12-month trial in the sea at Kure showed barnacles and algae taking hold less readily. We are also considering hulls and ocean-going ships.

For boat owners, shipyards and marine parts makers

Talk to us about this use

The problem

Fouling on a ship’s underwater surfaces is known to increase fuel use (source: IMO). Once barnacles and algae have settled, removing them takes work too.

The bottom of a boat out of the water, thick with shellfish and algae
Kurahashi Island, Kure (April 2025)

What we do

We treat the surface of propellers and other parts with plasma and bond a fluorine-based antifouling agent to it, leaving a surface barnacles and algae struggle to grip. We use no copper, silver or other biocides.

How the treatment works

Where things stand, and what to know

  • We start with parts about the size of a football, which fit our current equipment.

Stage and evidence

Each claim carries its own stage, and who confirmed it where that is on record. Results of Professor Kuroda’s research are shown apart from our own trials.

Ship propellers (brass)

We bond a fluorine-based antifouling agent to the surface of brass propellers so barnacles and algae find it harder to take hold.

  • Stage: Proven, Our own work

    We tested a treated brass propeller in the sea at Kure (Marine Craft Kazenoko) for 12 months and saw barnacles and algae take hold less readily.

Where the technology comes from: Kuroda’s research

Published results of KAKEN grant 22K04725, led by Professor Kuroda, our technical supervisor. We list them apart from our own trials.

  • Stage: Proven, KAKEN grant (Kuroda’s research)

    In the published report of KAKEN grant 22K04725, led by Professor Kuroda, our technical supervisor, fouling was also held back on a ship propeller; on a propeller run almost every day, part of the treatment wore away within five months.

    Source: Published report of KAKEN grant 22K04725

Related uses

Talk to us about “Ship propellers (brass)”
The brass propeller used in the trial, fitted to a boat
Kure (Marine Craft Kazenoko)
A treated brass propeller. Even coated in oil-based ink, it wipes clean with a rub of the finger under water.
  • The same brass propeller from another angle
  • A brass propeller under a boat’s hull, with a marina behind it

Ship bottoms, hulls and rudders

Using the treatment on a ship’s underwater parts, such as the bottom, the hull and the rudder.

  • Stage: Concept,

    We are considering holding back fouling on a ship’s underwater parts, such as the bottom, the hull and the rudder. We start with parts about the size of a football, which fit our current equipment.

Related uses

Talk to us about “Ship bottoms, hulls and rudders”
A boat lifted by a mobile boat hoist, its hull bottom and propellers showing

Ocean-going ships

Using the treatment to cut the marine life that ocean-going ships carry from one sea to another.

  • Stage: Concept,

    We are considering reducing the marine life that grows on ocean-going ships, so fewer non-native species are carried across the seas.

Related uses

Talk to us about “Ocean-going ships”
A ferry coming in to port

Ways to work with us

How to read the stages

Stage: Proven,
Results checked at sea or in the field, and on record
Stage: Being tested,
Trials, prototypes or development under way
Stage: Concept,
At the planning stage, including ideas shown as exhibits or prototypes

Content last checked:

Tell us what you would like to try with this use, or what is going wrong.

Talk to us about this use See other uses