.F04 File

The f04 file extension is mainly related to HEC-RAS software and used for one of its flow files.

HEC-RAS is a Hydrologic Engineering Centers River Analysis System developed by US Army Corps of Engineers.

Files with f04 file extension are flow files from  Hydrologic Engineering Centers River Analysis System by US Army.

How to open:

You should be able to work with these files using HEC-RAS program.

How to convert:

Probably cannot be converted to other formats.