Harwood Marine

Gas Injected Liquid Lubrication

Do you ever wonder what it would be like if there were an easy, effective, and efficient practice to dramatically reduce Global CO 2 emissions?

What if we told you we had a solution that would save fuel and gas emissions of most types of vessels and marine crafts.

At Harwood Marine, we are openly sharing our Gas Injected Liquid Lubrication technology to work in partnership with large international shipbuilders and shipping companies, in a global attempt to produce clearer seas and fresher air for the next generation.

What is GILLS?

GILLS (Gas Injected Liquid Lubrication System) is a system used to reduce the hull drag of large ocean vessels. This is achieved by generating ultra-fine microbubbles by applying the physical phenomena Kelvin-Helmholtz Instability.

Mr Yoshiaki Takahashi developed and tested GILLS at R & D Engineering in Tokyo, Japan. Our managing director, Ross Roberts, has collaborated with Mr. Takahashi for the last decade.

GILLS units can be installed on new or existing vessels, through easy to install components. Our team provides on request, an evaluation of each proposed vessel, and estimated frictional drag reduction, as well as a commercial offer and can provide clients with patented GILLS Vortex Generators, technical drawings, an equipment list, and an installation guideline to ensure that the installation process is seamless.

How does GILLS work?

This unique process involves the release of microbubbles, which stay in the water as the vessel moves, forming a cloud with hull-tightening forces on it.

Hull-tightening microbubbles reduce any hull drag on vessels that go through the cloud. This action reduces drag, fuel, Co2 and greenhouse gasses.

The GILLS units are mounted on the side of the ship’s hull, and corresponding flow lines so that the generated microbubbles enter the ship’s hull boundary layer reducing frictional drag.

Full-scale testing has shown that, with the correct operation, the GILLS units can produce a net power saving of 5-15 per cent for ships.

How will using GILLS benefit me?

GILLS is the technological advancement that could help save marine life, by reducing hull growth and biofouling, gas emissions and propulsion energy of ships and marine vessels and create a brighter feature for the next generation.

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Emission reduction


EEDI ship compliance


Reduction in docking cost

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Fuel tank redundancy increase


Reduced engine wear

Eager to learn more?

If you are interested in installing the GILLS units to your vessel, or want to learn more, get in touch with our team today.