BaconIsMyBFF

Question: Wouldn't the tidal wave Imhotep summons come towards the blimp from the front? Since O'Connell is behind him, following the clues left by his son. (01:18:05)

Answer: Imhotep's spell causes the river to overflow and create a gigantic wave. The river is flowing in the direction the blimp is going, so the wave comes from behind the blimp.

BaconIsMyBFF

Answer: I know this is an old question, but to be clear, O'Connell is actually ahead of Imhotep at that point in the movie. They arrive at Ahm Shere earlier and setup the ambush. So, the wave coming up behind them is actually correct.