Photo/Illutration The Japan Coast Guard on May 20 surveys an area where the tiny islet of Esanbehanakitakojima once emerged. The outcrop was located about 500 meters from the coastal village of Sarufutsu in Hokkaido. (Asahi Shimbun file photo)

The Japan Coast Guard on Sept. 24 said it still cannot find an islet off Hokkaido that expands Japan’s territorial waters by about 0.03 square kilometer.

The Coast Guard will continue its survey on a shallow area where the Esanbehanakitakojima isle is now underwater. If the isle is considered a “low-tide elevation,” which appears at low tide but is submerged at high tide, it can be used as a base point for Japan’s territorial waters.

If Esanbehanakitakojima is not considered a low-tide elevation, Japan’s territorial waters will shrink. Regardless of the outcome, the range of Japan’s exclusive economic zone will remain the same.

A Coast Guard investigation in 1987 located the islet about 1.4 meters above sea level around 500 meters from the coast of Sarufutsu village near the northern tip of Hokkaido. It has since appeared on sea charts but has disappeared in real life.

An aerial inspection in November 2018 could not locate the islet.

In April and May this year, the Coast Guard checked the depth of the islet using sonic waves. It measured the tidal level for a month.

However, Coast Guard officials concluded that they needed more data to judge whether Esanbehanakitakojima isle is a low-tide elevation. So they decided to continue measuring the tidal level for another year.

According to sources, the Coast Guard in its latest study was unable to obtain data showing that the area is a low-tide elevation.