How do cetaceans get water?

Like all other mammals, cetaceans need fresh water to survive.  Although they are surrounded by water all the time, this ocean water is salt water.  These great mammals get their water primarily from their food.  The creatures they eat have water in their bodies.  This water is also salty, but not as much so as the ocean water; and cetacean kidneys have developed to be able to filter out the salt in the water that comes from their prey.