Chao Phraya River bus cruise + Royal Palace

Chao Phraya River is a major river running through Bangkok. From the BTS station above east bank of the river, you can embark the water bus. Be aware that local water bus pier and private hire pier is similar and can be confusing. The one you see with the booth is the right one. We bought the tourist use one day pass for 150 Bahts per head, and hopped on the express way (shown in Orange Flag on the tip of each vessel). Each stop is marked alphanumeric (e.g. N8). At N8 stop you can either walk of hop on the TukTuk to the royal palace. I was with group of 5, so was hard to negotiate. Eventally we took their initial offer of 50 Bhats for single ride.
The Royal palace is accessible free of charge but if you wish to see the inner circle, you need to pay 400 Bahts per head (for those under 120cm is free of charge). Another thing you need to be aware of is your attire. No short pants is allowed. They can lend you the clothes to cover. But the queue for this service seems to be very long, so I recommend you to be prepared beforehand.
The whole place does not have any aircon besides the textile shop aside the entrance so I warn you to be prepared to the sizzling heat in and out of the area.
To get a taxi from this place may be another difficult job. I had to negotiate 10 taxis until I bumped into a normal one who would just charge by meters. The worst one you want to engage yourselves is the one who would drop by at souvenir shop. This is very tricky.