Honda Motor will start demonstration tests in August on a battery-powered outboard motor in the western Japanese city of Matsue with the goal of achieving carbon-free waterborne transportation.

In the tests, a prototype of the outboard unit will be installed on a pleasure boat that sails through the moat around Matsue Castle.

Honda demonstrated to the public on Wednesday how the battery-powered motor would work on a pleasure boat.

The outboard unit has a motor and lithium-ion batteries normally for use in motorcycles. While cruising, it is free of carbon emissions and produces less vibrations and noise compared to conventional engines.

Honda says fitting the entire fleet of pleasure boats there with the outboard units is projected to reduce carbon dioxide emissions by 47 tons per year.

A pleasure boat skipper says the battery-powered unit is very quiet and it is easy for him and passengers to hear what they say to each other.

Honda has yet to decide on using the outboard unit for practical applications. But the automaker plans to use the trials to study the unit's performance and impact on pleasure boat operations.

A Honda official says the tests should be an important step forward in the company's efforts to achieve carbon-free water transportation.

He says his staff will check the unit's practical efficiency and explore a way to ensure commercial viability so it can serve many people as soon as possible.