Trip Up the river by Speed Boat is the way to go
Came by cruise ship and booked this tour on our own instead of ship excursion. Trip up the Saigon river in the private speed boat was worth it in and of itself! Tunnels were very interesting, however I was claustrophobic and bailed. We did shoot the heavy artillery though, wow that was fun!
As Americans it is a tour that will sadden you and upset you at the same time. This war area was not a fun place for our soldiers, it will bring a tear to your eyes.
Book the earliest trip in the morning so you are one of the first guests there. It is a very popular spot and gets very busy!