We just visited Damneon Saduak Floating Market in Ratchaburi, Thailand. It is a famous floating market built along a man made canal in Ratchaburi. Sellers row boats along a narrow canal and sell things. The market usually starts early around 7 AM but does not reaches its peak until around 9 AM when lots and lots of tourists flood the market and turn the market into Floating Tourists! If you really want to enjoy the market, I advise to got there before 7 AM in the morning and take a boat ride. A boat ride will take around 45 mins and cost 100 baht per head or 500 baht per boat (maximum 6 per boat).
After the boat ride, walk along the canal and take some photos. By this time, the market would already be packed with tourist boats, and you will see a real traffic jam. The weather becomes extremely hot so it is not a good time to take a boat ride at this time anymore. The market usually finishes around noon.