From Sibu, I took an express boat up the Rejang River to Kapit. About half a dozen companies do the 130km journey and you can see the times of their boats at the ferry terminal. I took one at 8.30am which was full of locals and school kids and we passed by modern longhouses built out of bricks and concrete and painted the same shade of blue - some with 50-odd doors. The trip took about 4 hours and cost RM20.
I left Kuching on an express boat to Sibu. First you have to get to the Express ferry terminal which is located at Pending, about 6-7km from the city centre. We decided to take a taxi there which cost RM20. Boats leave at 8.30am and the trip takes about 5 hours. You'll pass by some heavy industry along the Sarawak River before you head across the South China sea to the mouth of the Rejang River. On the way up the Rejang you'll pass lots of logging ports and saw mills plus see piles of logs along the banks and barges pulling piles of them along the river. The boat cost me RM45 in March 2009.
Going to Sibu, after some disucssion, we decided to try out the fast craft from Kuching for some experience of it. It was a WHOPPING 5 hours of ride! And the whole journey does not have any interesting view. Either the seas or the trees.
For just abit more money, we took a plane back from Sibu Airport in just about 1/2 hour.
Travel by boat only if you have tons of time to spare.