It is easy to feel intimidated by a city the size of London. Not just for its 607 sq. miles (double NYC) and population of 9 million people, but for the intensity of the experiences and attractions that lie within its sprawling streets and neighborhoods.
Of course, you can always get around London in an Uber or a traditional black cab. They tend to call them cabs rather than taxis, as Americans may be used to.
It is more expensive though so choose wisely. The River Bus is operated by Uber Boat by Thames Clipper. They operate in three zones: West, Central and East.