In their sleep? It's hard to say. Unless they wrote it down how would you know?
Yes. Sperm whales sleep vertically with head down.
they swim when they sleep
In water
Yes.
Killer Whales sleep by floating on the surface.
At the bottom of the ocean!
they sleep and like the tropical water
No. While they do sleep in the Summer, they do not sleep any more in the Summer than in the Winter.
It is not known what time of the day blue whales sleep. The blue whale is one of the largest and heaviest animals in the world.
They don't drown because some whales go up to shore and sleep up there so then they don't drowned.
Sometimes,but not always.
No, in the open ocean.