The helicopter crew reported that they had come under fire and with that report, Rogers turned his ship around and, with the frigate , moved to intercept the gunboats. By doing so, "Vincennes" crossed into Iranian waters herself. As the US ships approached, the Iranian gunboats maneuvered, in what Rogers claimed was a threatening fashion. Rogers requested permission to fire and permission was granted by command, without knowing that "Vincennes" had crossed into Iranian waters. "Vincennes" and "Elmer Montgomery" commenced fire upon the gunboats at 9:43 a.m., scoring several hits on the gunboats, sinking two and damaging another.