Shamu is going public. SeaWorld Parks & Entertainment has filed initial paperwork to become a publicly traded company. The move comes three years after a $2.3 billion buyout by Blackstone Group, which will likely maintain a majority stake in a publicly traded company. The IPO is expected to raise between $500 million and $700 million. SeaWorld Entertainment, which owns SeaWorld, Busch Gardens, and other theme parks, earned $86 million in the first nine months of this year, up 73% from the year before.