Kayaking on the sound allows visitors to explore independently, finds Joe Dodgshun.
Despite the breathtaking scenery that has already passed below our GA8 Airvan since it left Queenstown, nothing can prepare for the first view of Milford Sound.
Sheer cliff faces plummet hundreds of metres to the rainforest-clad valley floor; beech trees cling to cracks in the rock and countless waterfalls launch into space; morning clouds still linger on the tops of razor-tipped mountains; and finally, as we approach our destination, the valley floor disappears beneath the shimmering waters of the sound itself.
We are here to try Southern Discoveries' new kayaking trip, which leaves from the company's refurbished Discovery Centre.
But first there's time for a trip on The Lady of the Sounds, tucking into a Kiwi barbecue brunch in the sun, while cruising up the sound which, as we are informed over the PA system, was not formed by rivers but a fiord gouged out by glaciers.
As we follow the path of the ancient ice, the boat slows and draws close to the cliffs for an encounter with fur seals and a view of the comical waddle of a Fiordland crested penguin.
The Lady of the Sounds pulls even closer to one waterfall and the more inquisitive among our group quickly need a towel.
Before we know it, we have reached the sound's exit to the Tasman Sea, where Captain James Cook twice sailed past, oblivious to the existence of Milford Sound due to its narrow entry point.
After a short ride back up the sound, we disembark at the Discovery Centre to experience its underwater observatory, 10m below the surface. Here baskets growing black coral, usually found only at much greater depths, attract an array of fish, sea stars and sometimes seals.
Tearing ourselves away from the 360-degree expanse of windows, we ascend the spiral staircase to check out our kayaks and, after a safety briefing, head out into the sound.
The kayaks are almost impossible to tip - even when a certain writer is almost washed on to a beach while taking a photo - so having previous experience is not an issue.
Our one-hour paddle takes us around Harrison Cove, which affords dramatic views up Harrison Valley to the Pembroke Glacier.
After flying, cruising and admiring the sound from underwater, exploring it under your own steam is rewarding and the grand scale of the towering mountains is awe-inspiring.
If he saw the sound from this perspective, even Rudyard Kipling - who described the sound as the "eighth wonder of the world" - might have been lost for words.
Southern Discoveries' kayaking combo: Includes a cruise, Discovery Centre visit and one-hour kayak and starts from $169 per person. The flight-inclusive package from Queenstown costs $585 per person.
Joe Dodgshun travelled as a guest of Glenorchy Air and Southern Discoveries.