PLEASE don't believe everything you read about Sea World. Since you are in Australia I can't exactly say to visit the park and see for you yourself how well the animals are kept, so all I can do is ask you not to believe everything you read since much of it is written by activists, many of whom would rather the orca be dead than in captivity. If you have any questions or concerns about what you have read, please reach out to someone who supports the park or has spent a lot of time there. I never understand why nobody has bothered to ask ME questions, no matter how many times I've offered an insider's view. I am not 100% Sea World, but as someone who has spent many years on the inside, so to speak, I can confirm or deny a lot of the stuff that has been written about the park.
A few months ago some school children here in Arizona got to see the movie Blackfish. I'm not real sure why they showed it in a grade school, but that part is irrelevant. My point is, that after watching the movie, they asked questions. They didn't automatically believe what the movie was claiming so they wrote letters to Sea World and asked questions. You know what Sea World did? Not only did they reply to the letters, but they sent a group out to the school to speak to the kids in person. I was so impressed by these kids, though, because they had the sense to ask questions and not just blindly believe the movie, but yet adults just blindly believe.
Sea World is not perfect. I'll be the first to say that. But they aren't the horrible place PETA and the makers of Blackfish want people to believe. I wish they would stop the shows. I wouldn't mind if they stopped the breeding program, but they are so much more than that. They rescue injured and stranded sea life and they rehab then release back into the wild. Occasionally an animal is deemed unreleasable due to injury and it ends up living at the park for the rest of its life, but fortunately, that doesn't happen very often.
You said you once gave Sea World the benefit of the doubt, but now you don't. I would like you to reconsider that. They no longer capture wild orca or dolphin for their parks and haven't since the 1970s. Do some more reading. Ask questions. I have tons of pictures and some video of the park, both during shows and between shows that proves some of what Blackfish has stated is a flat-out lie. I'm more than happy to share those with anyone who is interested in seeing them and learning the other side of things.