It's a shame you didn't do the tideway on Sat as this was the day of the Great River Race when literally hundreds of boats of all sorts row from Richmond to Greenwich, it is a spectacular sight!
The weekend was also the Thames River Festival which it sounds like to wandered into. The highlight for me was a two hour trip on a the Sailing Barge Lady Daphne which went under a raised tower bridge twice (For £10) - will post some pictures when I get the chance.
Tim
Edited to say that I also had my first trip on one of the Thames Clipper Catamarans to the O2, we went after it went dark and my they can shift when they get in a bit of open water!