Over millions of years of evoloution whales and dolphins nostrils moved to the top of their head. This allows them to breath by surfacing instead of them sticking their whole head out of the water. The first thing a newborn dolphin must do is to go to the surface to breathe. But the baby can not swim so its mother and a another dolphin will help push the baby to the surface for its first breath of air. The baby will be able to swim in about 30 min.
Dolphins are fast swimmers.
When a speeding boat passes the bottlenose dolphin, it will start to race out in front . They will take off hitting the water and keep going. Dolphins navigate by following the hills and mountains of the ocean floor, by tracking the sun, by sensing currents, and by tasting the water along the journey. A dolphin's sound probably originated in its nasal passages. These nasal passages are located on the top of the head.