Last year, Yamaha unveiled its Breeze10 autonomous, radar-equipped boat for inspecting dams. Today, the company announced that the robot boat's little sibling, the Water Strider, goes on market next month as a remote-controlled, herbicide-spreading vessel to reduce the labor costs of rice paddy cultivation.

Cultivating rice is a wet, messy, and often back-breaking task involving raising seedlings, ploughing the paddies, fertilizing them, planting the rice, weeding, pest control, cutting, gathering, and threshing – much of it still done by hand.

Responding to a Japanese government directive to reduce rice cultivation costs by 40 percent, Yamaha came up with the unmanned Water Strider to take over the job of spraying herbicide before and after rice planting and direct sowing. Though this is a job that has traditionally been done from the ridges between the paddies, the Water Strider takes the herbicide directly to the plants.

The Yamaha Water Strider's herbicide tank(Credit: Yamaha)

At 1.6 m (5.25 ft) in length, the Water Strider is an unassuming craft, but its compactness is necessary if it's to traverse rice paddies under remote control from a nearby operator. Its fiber-reinforced plastic hull is both lightweight and draws only about 5 cm (2 in) of water. It also acts as the spraying unit, dispensing the herbicide that is spread by wind generated by the propeller-driven engine.

Yamaha says that the bright contrasting livery of the Water Strider is designed to make it more visible among the rice plants. In addition, the boat contains shock-absorbing material and boasts what the company claims is the industry's first detachable cassette herbicide tank.

The Yamaha Water Strider goes on sale on April 25, for ¥975,000 (about US$8,500).

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