There is nothing irregular about this; Cedar Fair and Six Flags are already publicly traded. Actually right now Six Flags is valued at twice the price of Cedar Fair, $60 and $30 respectively. Six Flags went public underneath Premier in 1996 to raise $70 million at $16 a share. Cedar Fair went public in 1987 when the company was still just Cedar Point and Valleyfair, having only been founded for 4 years.
I am most familiar with both of these companies as I own stock in both.
Public trading is how companies most commonly seek investors, and is not an unusual move for an amusement park. While the 2000s were not the greatest for the American amusement park industry - between the travel hit after 9/11, high gas prices, and the 2008 recession - we are now seeing attendance and revenue stream bumps across the board for majority of amusement parks.
Back to SF and CF, the last good time for Cedar Fair investors was 2001/2002. Cedar Point is the primary indicator for the entire chain, which had just gotten done with a tremendously successful 1990s and was riding into the 2000s with Millennium Force. Stock value took a dip shortly after TTD, but has slowly rallied back to presently $60. It still remains to be seen if the Paramount Park chains will truly add value to the company as a whole.
Six Flags as many know has bounced in and out of bankruptcy for nearly a decade. They seem to finally have things on lock-down, getting rid of fledgeling parks and focusing on true park investment. Business forecasts are actually more hopeful for Six Flags than many others in the industry.
Will Sea World stock succeed? I would need to see some more of the numbers and a sense of Sea World's vision before dropping money. Sea World casts an intriguing tone - sort of an aquarium, sort of a zoo, and sort of an amusement park. Sea World is located in hot bedded tourist destinations, but is not a sure win with stiff competition between Disney, the San Diego Zoo, etc.
We have already seen one failed investment in Sea World Ohio in Aurora (later melded with Geauga Lake as Six Flags Worlds of Adventure). Outside of a proposed UAE Sea World, I have not heard any mention of growth for the chain. I would imagine China to be a possible option, as the government is currently trying to convert their economy to consumerism. Big whales, trimmed pathways, and a couple coasters will get you there!