Here's why:
* Blubber: Whale blubber is a thick layer of fat that acts as insulation and provides buoyancy. It's less dense than water, helping them stay afloat.
* Lungs: Whales have enormous lungs that can hold a tremendous amount of air. When they breathe, they inhale a massive volume of air, which increases their buoyancy further.
* Skeletal Structure: Their bones are lightweight and porous, contributing to their overall buoyancy.
However, there are some instances where whales might sink:
* Death: When a whale dies, its body loses its ability to regulate buoyancy. The lungs deflate, and the decomposition process releases gases that can cause the body to sink.
* Entanglement: Whales can become entangled in fishing gear or other debris, which can weigh them down and prevent them from surfacing.
* Disease or Injury: Whales suffering from illness or injury may be too weak to swim to the surface, leading to them sinking.
It's important to remember that whales are incredibly strong and adapted to their environment. Their bodies are designed to stay afloat, and sinking is usually a result of unnatural circumstances.