The Sun Kosi, the river of the gold, offers the longest trip in Nepal in terms of river days. It has many tributaries entering from the north that drain Himalayan peaks including the mighty mount Everest. The character of the river changes with amazing wide valley sections and large sandy islands becoming narrow jungle gorges and corridors.There is only one large village on the river, the hardest rapid, Hakapur is named after it. The upper section is known as the Bhote Kosi, an adrenaline charged section of river described separately in this guide. The commercial trips start at Dolalghat, which is close to the confluence of the Bhote Kosi and the Indrawati.Expect the trip to take 10 days, this may include a lay-over day. Post monsoon it can be rafted in 8 days, 6 in a kayak.

Transportation to the river
The Sun Kosi has the great advantage of having a put-in point near Kathmandu. You could expect the bus to take about three hours, which is ideal to unpack, have lunch and depart at the start of the afternoon.

On the river
This river starts with easy rapids and builds up to a climax at about the halfway point. From there it remains at a good level through the jungle corridor where it flattens considerably before a finale at Big Dipper (4).

On the first day you are likely to encounter big and bouncy wave trains at class 2-3 and you may reach Meat Grinder (4-) close to the confluence of the Tamba Kosi. From here class 3+ to 4- is the order of the day, with some rapids like High Anxiety (4-) which are just massive surf waves during early October descents.

The hardest rapid Hakapur (5-) is just before the halfway point and often a layover day follows at Little Devisthan beach. Below here the Dudh Kosi enters and the river narrows into the jungle corridor - Imaginative names of rapids within (Rhino Rock, No Quiche, Dummy to the wall, Roller coaster, El Wasto!, Arthur Daley?)

All the above in the class 4 region.
The river continues then with several more rapids at a lower grade. The Arun and Tamur rivers join just before the Sun Kosi breaks out of the valley it has been held in for 270km into a vast wide plain taking it eventually into the bay of Bengal.

In a kayak it can be done more quickly but the thought of a self-sufficient trip of that length would make me think twice - most raft operators offer good deals to kayakers (especially early season) and I would recommend using raft support or tagging along to a scheduled raft departure.

Ten days is a long time on a river - the only other advice is to bear in mind that you are confined to the area of an 8 man raft for 8-10 days with people who you may not have had chance to get to know beforehand. Lay-over days are a great way of breaking up that time - check if the operator you use includes that option.

Lastly, the journey to the river may be short but the journey back ain't ... unless you fly, you're looking at a 16 to 20 hours bus journey from hell (all part of the adventure!?)