What was the water temperature when the titanic sank?

32 degrees (F)

Explanation:

A water temperature of a seemingly warm 79 degrees (F) can lead to death after prolonged exposure, a water temperature of 50 degrees can lead to death in around an hour, and a water temperature of 32 degrees – like the ocean water on the night the Titanic sank – can lead to death in as few as 15 minutes.

uncle sam would be tossing and turning in his grave : *)