Having started a previous cruise in Bangkok I opted to stay in the Laem Chebang area. THe first day was "a day in the Thai Countryside and was interesting but not out of this world. The second morning was a visit to the "Tiger Zoo" which also had Crocodiles and Elephants and excellent shows with each.
On the island of Ko Samui, the day before, we had watched monkeys harvesting coconuts.
We actually had 4 ports in Vietnam. The best of the tours for me was the CuChi tunnels out of Phu Myu, where we had an opportunity to understand the war from a participant's point of view. Saigon was also available but a long distance from the port. Da Nang is a wonderful busy city. In Halong Bay tours were offered to Hanoi and Haiphong which were tiring and of medium quality, while everyone raved about the caves available on a 3-hour boat tour right off the vessel.
As port of disembarkation I did not take a "tour" here but it is a wonderful vibrant city with a lot to do. Ocean Terminal sits right in the heart of all the activity.