How dolphin and whales sleep

Ever wonder how dolphins or whales sleep? They’re mammals just like we are and need oxygen. Well, since when we humans are asleep, we are completely unconscious and do not have to brain capacity to support active thoughts and movement. Then the question is, if dolphins and whales
are just like we are, wouldn’t they drown if they were to fall asleep in the ocean?The answer to that question is obviously no considering dolphins and whales are very much still alive.There is involuntary and voluntary breathing. We humans are involuntary, which means that if we do not breathe, our bodies will automatically try to induce air. Since dolphins and whales have a unique respiratory system which allows them to hold in air for a long period of time, they are voluntary breathers. Voluntary breathers are also known as conscious breathers, which simply means that they need to be conscious in order to breathe because they control when to and when not to breathe.