What blue ocean means
Kim and Mauborgne published the article "Blue Ocean Strategy" in Harvard Business Review in October 2004, and the book followed in 2005. The central idea, which they call value innovation, had already appeared in an article of theirs from 1997. According to their website, it rests on a study of more than 150 strategic moves in more than 30 industries over 100 years.
Red oceans are all the industries that exist today, with known boundaries and rules, where companies take share from one another. Blue oceans are the industries that don't exist yet, where demand gets created. The authors study moves and set companies and industries aside as the unit, because, as they write, no company is consistently excellent.
Two misreadings come up with this topic, and you can check both against the original.
The first is believing you have to invent something. The 2004 article says the opposite: blue oceans seldom result from technological innovation, and it's much more common for one to be created from within a red ocean, when a company expands the boundaries of its industry.
The second is believing the water stays blue. The authors write that such companies usually go ten to 15 years without credible challenges, and their main example was Cirque du Soleil, whose revenue had grown 22-fold in ten years. On 30 June 2020 Cirque obtained creditor protection in Canada, with liabilities of about $1.6 billion. The pandemic had closed all its shows, and it was already heavily indebted after a series of acquisitions. In November 2020 it left the process through a sale to its secured lenders. That doesn't refute the method, because the cause lay elsewhere, but it shows that a good move doesn't protect a company from whatever comes next.