Topic 01 - Invention of the fish finder

In 1948, a device for detecting fish underwater was developed in Nagasaki, Japan. The Furuno brothers, Kiyotaka and Kiyokata, the owners of a small marine electrical company in a small port of Japan, developed this amazing new technology.

One day, an experienced fisherman talked to the brothers "I know where fish are. And I can guess its quantity, too!" This private talk between the Furuno brothers and the fisherman provided Kiyotaka an inspiration of developing a fish finder. "Air bubbles.” said the fisherman, “When air bubbles rise to the sea surface, it means there is fish school down below.” - This was the secret for fishing. It was a well-known fact that a sound wave reflects when it hits against a bubble, what Kiyotaka instantly thought was that it can be used for detecting bubbles in order to find fish. This conversation with the experienced fisherman had become an important trigger for developing fish finders.


Kiyotaka, the older brother at the age of 16, started developing a fish finder using scrap materials, and repeated the experiment. Kiyokata, the younger brother, took the prototype onboard, and put it to the test again and again. In the early days of development, it didn’t work as well as they expected. Many times Kiyokata was thrown overboard by the angry captain, as Kiyotaka thought he found a fish school, which really was a swarm of jellyfish. However, gradual improvement of the equipment lead to successfully finding fish. The positive results gradually changed the fishermen's attitude toward the brothers. As a tester and an instructor of fish finder, Kiyokata went on various vessels, which resulted in enough great catches to prove the performance of their fish finder. Eventually Kiyokata was nicknamed as the "god of sardine" since he became able to successfully find fish schools everywhere.


The invention of the fish finder was the materialization of an engineering primitive seed - a boy's dream of "how wonderful if I could see underwater." It has been already more than 60 years since the first fish finder was introduced in the market. Before this technology was available, fishermen depended solely on their intuition and experience. However, the Furuno brothers’ fish finder dramatically changed fishing into a modern, scientific operation.


The early model of fish finder
- The world's first practical fish finder commercialized -

The world's first fish finder was commercialized by the Furuno brothers in 1948 in Nagasaki, Japan. The early model was a pen recorder that utilized specially processed recording paper to record the found objects underwater. The operation was very easy, it only had a power switch, a sensitivity adjustment and a search range selector.