Seeing Tokyo at street level is fascinating enough, but viewing the city from aboard a Sumida River Line water bus will give you an entirely new perspective on the place. There are a number of different sightseeing cruises on offer, with the route from Asakusa to Odaiba Seaside Park being one of the most popular, and the run to the Hama-rikyu Gardens another. As you pass under various bridges, a guide will point out the traces of the old Edo capital that remain and offer some history.
Tokyo Cruise Asakusa Pier is the primary hub for these relaxing little cruisers, and they also go around Asakusa Harbor. If you're here in summer, consider taking the Tokyo Bay Yukata Cruise, a beer garden on the water that is one of the coolest places to be in every sense. If you wear a yukata, the price drops by almost half. These boats leave from Takeshiba Pier in Hamamatsucho.