No.
While they do sleep in the Summer, they do not sleep any more in the Summer than in the Winter.
Yes. Sperm whales sleep vertically with head down.
they swim when they sleep
In water
Yes.
Killer Whales sleep by floating on the surface.
Estivation is summer sleep; hibernation is winter sleep.
At the bottom of the ocean!
they sleep and like the tropical water
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.
Sometimes,but not always.
No, in the open ocean.
They don't drown because some whales go up to shore and sleep up there so then they don't drowned.