The man was not wearing a lifejacket at the time of the incident.
Indiana Conservation Officers are searching for a 70-year-old man last seen in the water at Grandview Lake.
The search is using boats and side-scan sonar.
Just after 11 a.m., responders were notified the man was in the water near his boat when he went under and did not resurface. The man was not wearing a lifejacket at the time of the incident.
The identity of the man is being withheld pending family notification. Additional information will be released as it becomes available.
Conservation Officers are being assisted by the Bartholomew County Sheriff’s Department, Southwest Volunteer Fire Department, Harrison Township Volunteer Fire Department, Columbus Township Fire Department and Columbus Regional Heath.