Unfortunately the location of the date line is indeterminate in international waters. Kiribati claims to be first, so I will give them the benefit of the doubt - which means that they will be the first to witness the horrible destruction of the Earth.
Personally, if I ever visit New Zealand some day, I would also like to visit Christmas Island for a few reasons as well. Otherwise I will just "keep away from the water."
By the way, I hope that New Zealand experiences a wonderful Christmas (a few days after "the end")!
When it comes to havoc, no one wreaks like me! - Dr. Heinz Doofenshmirtz
I will never be good and that's not bad. - Ban-Anon