While it was rather difficult to find where to board the boat at Waterloo (it's at the London Eye), it was worth the search. We had a beautiful sunny day and saw so much from the water to and from Greenwich.
I rated this tour low because of the cost. Because we toured so much on the first hop off, we were too exhausted to hop on and off anywhere else. Also time was a factor. It would have been considerably less expensive to just use my London Oyster Pass I purchased instead...6 GPS instead of 18 GPS I paid for this pass.
Wonderful way to get around London! Comfortable, clean boats with professional and welcoming crew. We rode the entire circuit with our River Roamer tickets and simply enjoyed the comfort of seeing the city while resting our overused feet and sipping a quite good Cappuccino. I'd highly recommend the Thames Clipper River Roamer: Hop On Hop Off. This is one we will do again when we return.