[QUOTE=super termoli] If you start with the premise that the original design was valid and made for a ship with even outstanding stability, I cannot see what they could have done to her to keep the stability reasonable with as many decks thrown on purely as an afterthought. And yet, I cannot imagine that authorities would have allowed an unstable vessel to operate for over a decade.
Super it is puzzeling.
Cruise ships are typically constructed to maximize revenue generating space and the idea to have so much "wasted" stability on the original construction seems unlikely. However, the intact and damage stability would have to be completely re-done,(Flag State) Panama I believe in this case would have to approve everything. When a cruise ship undergos major conversion the U.S. requires plan review and conduct oversight if they embark U.S. Passengers. I have done two conversions in Greece and the Med inter-island trade is quite interesting.
It is a terrible situation and it would be uncomfortable to find out the proper stability calcs were not accurate.
In regard to a decade of service if the vessel always sailed intact it would be fine, the problem would emerge with damage stability or subdivision.