Doubtful Sound Overnight Cruises. Escape the hustle bustle of city life on this relaxing overnight cruise that takes you deep inside one of the most spectacular regions in New Zealand - Doubtful Sound with HotelClub. Why book this tour: Soak up the stunning surrounds of Doubtful Sound. Feel the awesome power of Nature here the remoteness, the wilderness and the peace. Enjoy a sumptuous three course buffet served with some of the region’s finest produce.