If the color of the taxi I have boarded is anything to go by, I could be in New York or Chicago, maybe even Kolkata. Instead, this particular yellow cab is ferrying me around Tokyo and rather than vying for lane space with trucks, buses and passenger vehicles, it's chugging along some of the little-traversed waterways of the Japanese capital.

The scenery seems to fluctuate at each bend in the river, no more so than after Capt. Katsuaki Hirano has navigated us through the massive red iron gates of the Ogibashi Komon Lock, where a gaggle of giggly schoolboys waves us through with a cheery "Ha-ro!"

We are now traversing a narrow stretch of the Onagigawa, a canal built at the behest of Tokugawa Ieyasu in the early 17th century to transport military provisions such as salt to the capital, which was then known as Edo.