The Kepler and the Dusky have so little in common and so many differences that it is mistaken to refer to them both by the same term, "Track." The Kepler is extremely artificial - broad, smooth and steady, a Walkway gouged through the landscape. The Dusky follows natural lines - sometimes very narrow, often very rough and full of surprises to break your rhythm. You can hardly walk ten minutes without coming to a patch of deep mud, a steep climb or drop, fallen trees, even landslips, gullies, usually with water in them or awkward tree roots, though these do provide useful hand and footholds.
They both take you through forest and bush, along rivers and valleys, beside lakes and up above the bush line with spectacular views of mountain peaks stretching away to the horizon. The Kepler can be completed with dry boots. On the Dusky you will put on wet socks most mornings and squelch day after day with water oozing from your footwear. The Kepler can be managed comfortably in three days by someone of moderate fitness. The Dusky requires something like a minimum of six for someone really fit. Allowance should be made for when it is impassable. Every day extra adds a further day's rations to your pack.
On the Kepler gaiters are superfluous, and would even seem out of place, under the conditions most walkers encounter, though no doubt not in winter when there may be snow. For the Dusky gaiters are strongly recommended and welcome extra protection. If you've not walked with a stick before, the Dusky is a good place to start. Cut yourself a straight stem - hazel is ideal, birch suitable - 15-20mm in diameter, to reach from level ground to somewhere between your eyebrows and the tip of your nose. A branching point at the top can be used to form a thicker end to tell your hand when to grab hold. A further irregularity around armpit height is also useful for grip. Chamfer the bottom end to prevent it spreading and splitting. This also provides a point for better grip on the ground. An important benefit when walking with a staff is the additional point of contact with the ground, helping keep balance and take some of the strain, especially on rough terrain, when carrying a heavy load. Someone carrying a staff on the Kepler would look rather unusual.
On the Kepler it is extremely difficult to miss your way. Although the Dusky is well-marked and for the most part well-defined, you will lose your way more than once a day, even when striving not to - unless you know it particularly well. People seldom fall on the Kepler. Most people fall several times a day on the Dusky. A staff helps. The highest steps on the Kepler are man-made wooden staircases. On the Dusky the next foothold is sometimes at hip height, or that far below when descending, and you pull up or lower down on your arms, occasionally with the aid of fixed ropes. A staff sometimes is a hindrance - a small price to pay.
On the Dusky you will crawl on hands and knees to get yourself and your pack under fallen trees, you will clamber over other tangled masses of rocks and branches, land slips and tree falls not yet cleared, wade through water, slip on slimy logs, roots and branches - and curse them. Unheard of on the Kepler, where every trivial rivulet is bridged with a board - there's not even a walk-wire.
If you would like to get an idea of the Dusky, go on the walks at Manapouri, climb Skyline Ridge to the tussock tops. If lucky enough to have wet conditions, multiply the difficulties by a factor of about three to simulate the Dusky after a dry period.
It is understandable that visitors are officially discouraged from tackling the Dusky. It is in an entirely different category from the popular and well-known walks. You need to be far more self-sufficient. It is misleading if it is presented in the same format - same style brochure, for instance. Whatever you choose - enjoy your walk, have fun, but take care, stay safe.
LBDuck Here I sit in the hut at Spey, on this wet and dismal day, Centre pas is distant and bleak,and the track is now a flowing creek. But though my day in this hut is spent, I thank God it is not a sodden tent...... Was about 1980... and it bucketed down. Kintail hut the next day and the river had been flowing around the hut. The following day I made it to Loch Maree, using my pack as a bouyancy aid for about te last 1/3rd of the way as the Seaforth had backed that far up from the loch that the track was submerged.... fun times, good memories