Factual error: Throughout the end there is fire everywhere. All of that fire would consume any oxygen that was in the rooms and fill the rooms with heavy black smoke. They are walking and climbing everywhere without the effects that the smoke and lack of oxygen would have caused.
Factual error: In the scene where the ship encounters the tidal wave, the ship is located in the Mediterranean Sea and is struck by a tsunami generated by a sub-sea earthquake 130 miles off the coast of Crete. The Mediterranean is a relatively calm body of water compared to the Atlantic. Beyond that, a tsunami wave from even a major earthquake will pass almost unnoticed to ships at sea; tsunamis only rise up and become dangerous in shallow water on coastlines.
Factual error: When they first encounter the sliding red fire door it is supposedly hot to the touch, when the fire door is slid open it leads to the kitchens, the "fires" are the gas burners from the stoves. First of all, the ovens and stove tops on ships are run on electricity, not natural gas. These burners would not produce sufficient heat to make the room extremely hot, not even with hot steam from burst pipes.
Factual error: Throughout the movie, the characters talk of "the" engine room. The Queen Mary (aka Poseidon) has four engine rooms: forward port, forward starboard, aft port, and aft starboard. There are also four shaft alleys (one for each propeller shaft), along with two generator rooms and five boiler rooms.