Japan and three Southeast Asian nations will jointly survey the Strait of Malacca for hazards to shipping next year.
Indonesia, Malaysia and Singapore will map five priority locations in the congested channel, Japanese officials said.
Japanese shipping companies will provide funds and technical personnel.
The corridor is narrow and known accident black spot. It needs surveying on a regular basis to identify risks from underwater hazards such as wrecks or a shifting seabed.
Japan has taken part in similar surveys twice since the 1960s. Its participation in the upcoming survey was decided at a meeting in Malaysia in September.
The nation depends on the strait to import natural resources such as crude oil from the Middle East.