One of the ship's cooks, Charles Joughin, was able to survive much longer in the cold water than others because of the copious amounts of whiskey he had drank.
Joughin is briefly but memorably portrayed in "Titanic" as chugging a flask of alcohol before entering the water. This is based on reality — according to reports, Joughin grabbed two bottles of whiskey as the ship went down.
Joughin reported that he survived in the frigid northern Atlantic for at least two hours — most people died from hypothermia within 15 minutes.