While climbing the pyramid, Agent Simmons is talking to the captain of an air craft carrier about using the rail gun against Devastator. Simmons says "Now if you've got a battleship in the Gulf, and I know you do, you tell them to ready that weapon!" Unfortunately, the last battleship was decommissioned in 1992, so there's no way there's a battleship in the Gulf. The rail gun is later shown (correctly) being fired from a destroyer.