$12. Ride all day. Take as many water taxis as you want. Service does stop at 5PM. There are a number of destinations with your embarcation point being the Inner Harbor. Fell's Point and Fort McHenry are the most popular destinations and one could spend most of a day in either one. Fort McHenry does charge to get up close to the Fort and to the Museum, but there are plenty of free areas including a large lush field and a nature-rich sea wall trail which sometimes offers birding tours. Fell's Point is where most people stop and stay and dine, drink, shop and explore the old wharf-influenced streets with their vintage architecture. It is best if you are staying near the Inner harbor as you can walk from your hotel to the Water Taxi. Otherwise, you need to take a cab or bus (or pay to park your car) at the Inner Harbor embarkation point. Parking, paricularly can be pricey, The pilots and "first mates" on the Water Taxi can be quite taciturn, to say the least. They are not heavy in the charm department, but they are watchful and seem to take safety very seriously.