Aitutaki in the Cook Islands, with close ties to New Zealand, is a dream destination for would-be castaways.Blessed with a luminous aqua lagoon, lush peaks, sublime beaches bristling with palms, and some of the friendliest people in the South Pacific, Aitutaki ticks all the boxes for the perfect exotic tropical vacation. In many parts of the vacation destination, great white sharks are now plentiful, but cell phone signals are still…