Laos forum

There is no reasonable boat trip option since Luang Namtha is on the Nam Tha (river) while LP is on the Mekong. It's a 2 day boat trip by charter only to travel the Nam Tha river up to Luang Namtha from the Mekong. Your only real option is by road and it's not a bad trip but slow due to massive long road construction in the Oudom Xai area. The trip takes about 9 hours and can be done by minivan, big buses or my favorite, those mid-sized local public buses that tourists never take. These local buses for this route have two legs, the first from LP to Oudom Xai and the next from there to Luang Namtha and continuing to Huay Xai. Hopefully, the 2nd leg bus will be waiting for the first leg bus to arrive and will depart shortly thereafter which makes an ideal transition in Oudom Xai and if so the total travel time is the same as big buses. The big buses have much trouble navigating thru all the ongoing road construction (narrow lanes) and the minibuses are loaded with smelly falang tourists. Better to break away from the herd and endure the smelly local buses. Bound to see some hill tribe people on them who often get sick after about 20 minutes.

Any bus going from LP to Huay Xai or from Luang Namtha to Huay Xai will pass thru Vieng Phouka and you can get off there and is reachable in one day from LP. To get to Muang Sing in one day you would get the earliest bus out of LP to Luang Namtha and go directly to the central minivan bus station in Luang Namtha to hopefully get a minivan to Muang Sing but you'll probably miss the last bus. The main bus station on the outskirts of Luang Namtha doesn't have buses to Muang Sing. The Luang Namtha map at http://hobomaps.com has the minivan bus station indicated.