The dragon boats depart the wharf at 8:30pm. Make sure you get on a fullish boat, because 2 hours is a long time to have to give your undivided attention to performers because you are the only ones on the boat.
Performers play traditional woodwind, stringed instruments, the teacups and sing traditional folk songs. They obviously enjoy themselves, but unfortunately, I didn't get any of the jokes due to my nonexistent Vietnamese and their limited English. At the end of the performance, coloured lanterns are released onto the river. Apart from the performances being out on the river at night, it is pretty.