We booked an overnight in doubtful sound on the fjordland navigator boat. The journey to the sound is long. We took a coach from queenstown to lake manapouri. From there a ferry to the road which takes you to the sound where you board the boat.
The staff on the boat are great. Very knowledgeable about the area, there is a nature expert and a full staff including chef.
The views, the peaceful environment, the nature, seals, penguins all contribute to an amazing experience!
On top of that, the food is absolutely delicious!