These 40-minute narrated cruises give you a good visual overview of the river and a light history lesson. You can buy your tickets online or get them on the waterfront at any of the stops. No reservations are necessary and tours leave every 15 to 20 minutes.
You'll find a ticket booth and a boarding point for the cruise at 706 River Walk. Check the website for additional ticket booths and boarding points.
The same company also operates a river taxi, stopping at 39 points along the river. You can hail them from the River Walk (look for the Rio Taxi sign). You can now track their location via GPS on the website.