In comparing Milford Sound or Doubtful Sound, start with the premise that both are spectacular. The experience, however, does differ significantly and it's worth doing your research. Below we break down the pros and cons of each, including an analysis of their remoteness, size, cost, and the cruising experience, and cost. We also provide links to companies that operate in each area. Enjoy your trip!
Remoteness
Milford Sound: The Milford Road allows for direct access to the foot of Milford Sound: it can be reached from Queenstown on a day trip (4 hours) or even more quickly from Te Anau (2 hours). The ease of access doesn't necessarily detract from the Milford Sound experience, but it means that you will be sharing the waters with a host of other boats and people.
Doubtful Sound: There is no road to Doubtful Sound—first you must be transported by boat over Lake Manapouri and then by bus over Wilmot Pass—so it receives only a fraction of the visitors compared to Milford Sound. Doubtful Sound remains relatively untouched and is more of a wilderness experience.
Size of the Sounds
Milford Sound: Milford Sound is considerably smaller but feels more vertical and imposing than Doubtful Sound. When visiting Milford Sound one is constantly straining upward at the overhanging cliffs and sheer waterfalls.
Doubtful Sound: Doubtful Sound is three times longer than Milford Sound and ten times larger. It too has an abundance of impressive scenery but is more open and spread out.
Cruising Experience
Milford Sound: Milford Sound has an orderly system of 2-hour boat cruises that depart from the main dock and circle out to the Tasman Sea and back (it's a wonderful cruise). The loop through Milford Sound is fixed and at any given time there will be a handful of other boats in the vicinity.
Doubtful Sound: Cruises on Doubtful Sound, on the other hand, are not structured and the boats have freedom to explore. Overnight cruises on Doubtful Sound are much longer and allow people to swim, sea kayak, fish for their dinner, and take in the sunset and sunrise from the boat.
Cost
Milford Sound: 2-hour cruises start at $55. Visiting Milford Sound is undoubtedly cheaper than visiting Doubtful Sound because the cruises are shorter, the boats are bigger and have more passengers, and no additional transportation is required.
Doubtful Sound: Daytime cruises start at $210 and last 8 hours. Overnight cruises in Doubtful Sound start at $395.
Conclusion
Milford Sound is the most popular tourist destination in New Zealand and worthy of a visit. Avoid the day-trips to Doubtful Sound—they tend to be hurried and heavy on transportation. If it fits within your schedule and budget, you also should consider splurging for a Doubtful Sound overnight cruise on a small vessel. Those who overnight in Doubtful Sound consider it to be a highlight of their trip to New Zealand.
Milford Sound Cruises
Mitre Peak Cruises has smaller boats built specifically for Milford Sound and great staff. The first and last cruises of the day are best, before and after the influx of day-trippers from Queenstown ($55 USD for adults, $13 for children).
Doubtful Sound Cruises
Fiordland Expeditions runs a fantastic overnight cruise on the small Tutoko II with a maximum of 14 clients and often less (starting at $410 USD).
Deep Cove Charters offer highly regarded overnight trips on Doubtful Sound with a capacity of 12 clients (starting at $395 USD).