Class and Flag State of Megayachts

Hello Everybody,

I'm coming from Germany and I actually work on my diplomacy for the shipyard HDW in Kiel. The topic of the diplomacy is "Life-saving Appliances for Megayachts".
I need some help in finding out some information about the world's largest Yachts, I hope you can help me. It is of great interest for me which classification society and flag state are given for the vessels in the ranking list from 1 to 30.
Thanks for every answer and excuse my grammatical english.
Best regards