Playful dolphins just want to have fun
These are the dolphins from the Harderwijk Dolphinarium in the Netherlands. They do have a short show there in their natural sea water lagoon (not a pool), the Dolfijnendelta where most of the dolphins live. It's just a short show so not to have the Dolphins work too hard. This video is not from the show, but what they do at other times.
They are getting toys! The staff throws these floats into the water and the dolphins seem to love it. They free to play or to just leave them where they are, but they were actually waiting for the staff in the morning to throw the floats into the water and started playing straight away. Jumping over it, trying to sink it, push it and throw it. They threw it that hard that one of the float ended back up on land, with the other Dolphins looking at the thrower as if they were saying to him, what have you done, but not to worry there were many more floats!