South Korean shipbuilder Hanwha Ocean Co. said Wednesday it has succeeded in developing three key devices of a submarine sonar system.

They include a sonic depth finder, a sonar beacon and an underwater environment measuring apparatus, which could help boost the operational capability and viability of a submarine, Hanwha Ocean, formerly Daewoo Shipbuilding & Marine Engineering Co., said.

A sonic depth finder, or fathometer, uses sound waves to determine the depth of water, and a sonar beacon is an emergency pinger for submarines in distress.

South Korea has relied fully on imports for those devices, but their localization could cut costs by around 50 percent, Hanwha Ocean added.

The shipbuilder said they could be installed not only on existing submarines but also subs that will be built for domestic use or exports.

"The local development of those sonar devices is expected to contribute greatly to boosting South Korea's maritime defense capability," a company official said. "Hanwha Ocean will make continued localization efforts for the country's self-reliant defense."

Hanwha Ocean had earlier succeeded in localizing a vibration damper for vessels, which the company says will help boost warships' operational capabilities.

Hanwha Ocean is the shipbuilding arm of defense-to-energy Hanwha Group that has recently won regulatory approval for its purchase of a 49.3 percent stake in DSME and managerial control. (Yonhap)