Bottlenose dolphins are powerful swimmers with a foraging and travelling speed of about 5km/hour, and a cruising speed of about 10km/hour, although they can also swim at speeds around 37km/hour. 
It is impossible for them to swim this fast in a small concrete pool or tank. In the Ocean they can dive to depths of 600m for 15 minutes.
​When they surface in the Ocean their head will show, but generally not their beak (compare this to captivity where dolphins constantly have their beaks out of water).