How could they have expected Truman to never want to set foot outside Seahaven?
They knew the day would come and that it would be great tv
Why didn't they just let him take a trip to Fiji and make it miserable? They could have some asian family with cameras shadow him to record.
They could have faked the trip to Fiji (just another set) and make it as boring as his hometown...
That was why he was conditioned to fear boats and flying. He was also told there was nothing left to discover in the world.