We took the tour on the day
We took the tour on the day that we arrived which was perfect in terms of activity level. The narrator on the boat is very knowledgeable and funny but the loudspeakers can be extremely loud so seat yourself accordingly. The boats run frequently we got off at Greenwich and found a nice pub for lunch before we boarded for our return. Great way to see London from the water side and to get your bearings before you begin on foot.