HONOLULU — Firefighters here yesterday entered the fourth day of searching for a New York City man who disappeared while scuba diving.

Capt. Terry Seelig had said that if no new information were found by the end of the day yesterday, a decision could be made to terminate the search effort.

Matthew Curley went diving with a commercial tour group Monday in the Waialae-Kahala area.

When the dive ended, Curley was not with the group.

A single fin was found in the water Tuesday, and Island Divers, the tour group, identified it as the same type and size that Curley was using.

The Coast Guard suspended its search that night.

Seelig said water conditions were calmer yesterday, which can be helpful for rescue divers. Firefighters are expected to expand the search along Oahu’s eastern shore.