Getting there and away

Bus

There are two buses out of Muang Khua to Udomxai and they can get quite crowded.
Udomxai: Departs at 08:00, 13:30, taking about three hours and costing 40,000kip.

There are daily buses from Muang Khua to Dien Bien Phu in Vietnam. The buses leave from the opposite side of the river and you must get there under your own steam. Get there no later than 06:30 to have a better chance of getting a seat. You cannot get a Vietnamese visa at the border -- you must get the visa beforehand. Actual trip time varies tremendously depending on road conditions.
Dien Bien Phu: Departs at around 07:00 and costs 70,000kip, plus 2,000kip to cross the river.

Boat

The main mode of travel to and from Muang Khua is by boat, on the scenic Nam Ou River. Fast and slow boats go north to Phongsali and slow boats go south to Muang Ngoi and Nong Kiaow. Boats leave every day at around 08:00-09:00, whenever enough passengers turn up. It's best to get down to the boat landing by around 07.30 with a good book, to be sure. If there are not enough passengers, it will not depart and you will have to either wait until the next day or charter a whole boat to yourself.

Fast boats do the job quicker, but are a much less safe, pleasant and relaxing way to travel than the small slow boats. These are hardly a luxurious journey - boats are small, often cramped and crowded, have no toilet on board, and there is little movement to be had once on board - but they have a roof to protect from the sun, and offer a quieter, more peaceful way to watch the scenery pass.

Boats leave from the end of the road that leads down to the river - easy to spot because that's where all the boats are. The ticket man loiters down by the water's edge, and will help you find the right boat, though he speaks limited English.

A very small boat also makes the journey to the other side of the river, for 2,000 kip per person. This goes regularly throughout the day, and departs when there are enough passengers. You will probably be able to hire the whole boat if you are in a hurry, for about 15,000 kip.