My husband and two teenage boys took a cruise along the River Walk. It was around 8pm and while there was a crowd waiting to get on, it did not take long. The cruise is reasonably priced and you get a commentary about the history of the river and buildings along it.
Was a gorgeous summer night and the restaurants were packed making for quite a buzz as you toured the river. You can also take a taxi ride, but I do not think it includes a commentary.
Make sure you get there well before 9pm, as they close the rides right on time!
We had to come back a second night as they advertise "til late" but that is not the case.
Recommend it, but it is not a long ride.
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