They have a number of Saigon River day cruise and night cruise available for all types of budgets. The Day cruise usually goes around the Saigon River and to other parts of the South like in the Cu Chi Tunnels or the Mekong Delta or to then famous beach town of Vung Tau (which is a two hour boat ride away via a fast catamaran). The Saigon River is the life blood of Saigon and that is why Saigon is a major Port Area for goods since the 17th century as the City was built at the Saigon River. Most people do the Saigon River Dinner Cruise which is a 2 hour dinner and cruising along the Saigon River and the ferry terminal is just beside the end of Nguyen Hue Street.
The best way to get from HCMC to Vung Tau is aboard the high-speed hydrofoils. There are 6 or 7 departures per day and the trip only takes one hour. Cost for a round trip ticket is about US$10. The boats load and unload along the waterfront at the Bach Dang Wharf passenger quay in downtown HCMC, and they make a straight shot for Vung Tau.
There are two companies operating the hydros: Vina Express and Greenlines. I think their rates are exactly the same (as they should be in a communist country!) and they probably even use the same boats. The hydrofoils have seating for about 120 people--during my trip, maybe 1/4 of the seats were full. There were some locals on board, I think they get a big discount on the fare.
Here's a schedule from the Vina Express website:
HCMC to VT departures
0600, 0830, 1030, 1230, 1430, 1630
VT to HCMC departures
0600, 0830, 1030, 1230, 1430, 1600
If you take one of tose Mekong Delta tours you will be taken through the narrow channels among the little islands of the Delta. The wooden boats are strait, with room for 5 people in a row. The shores are all lined up with water palm trees that grow in the water.
The foliage is so thick that it made a perfect hideway for the Vietcong to hide when the USA planes appeared looking for targets.
You will be offered a traditional triangular hat as you enter the boat, but don?t feel obblied to wear it?
High-speed hydrofoils run from Saigon to Vung Tau and to the Mekong. The trip to Vung Tau only takes 1 hour and the ticket is about $10. You can catch these boats at the Bach Dang Wharf.
This is a very handy means of transportation. Hands are free for some other activity (e.g. smoking) and it was fast.