Chao Phraya River taxi part 1 Bangkok Thailand

The main river that runs through Bangkok is the Chao Phraya River (Thai: แม่น้ำเจ้าพระยา, pronounced roughly "Mae Nam Chao Phraya").
Key facts about the Chao Phraya River

It is the major river of Thailand and often called the "River of Kings."
Length: About 372 km (231 miles) from its origin in central Thailand to the Gulf of Thailand.
In Bangkok, it forms a wide, curving waterway that divides the city into two main sides: the historic old Bangkok (Thonburi side, west bank) and the modern downtown side (east bank with areas like Silom, Siam, Sukhumvit).
Many of Bangkok’s most famous sights are along its banks: Grand Palace, Wat Arun (Temple of Dawn), Wat Pho (Reclining Buddha), IconSiam mall, Asiatique night market, etc.

River taxis / Chao Phraya River boats
The public boat services on the Chao Phraya are one of the fastest, cheapest, and most scenic ways to get around central Bangkok, especially to avoid the city’s notorious traffic.
There are two main operators:

Chao Phraya Express Boat (the most common “river taxi”)
Orange-flag boats: The workhorse service. Run every 5–20 minutes (more frequent in rush hours), stop at almost every pier. Fare 15–16 baht flat.
Green-flag (Yellow-flag during rush hours): Faster, limited stops, slightly more expensive (~20–30 baht).
Blue-flag (Tourist Boat): Fewer stops, air-conditioned in some sections, all-day pass ~150–200 baht, includes English commentary.
No-flag/local boats: Very cheap (~10–13 baht), stop everywhere, usually more crowded and slower.


Major piers (from north to south, roughly):

Nonthaburi (northernmost)
Thewet
Phra Arthit (near Khao San Road)
Tha Chang (Grand Palace / Wat Phra Kaew)
Tha Tien (near Wat Pho)
Ratchawong
Sathorn (connects to BTS Skytrain at Saphan Taksin station — very useful transfer point)
Asiatique, etc.

Operating hours: ~6:00 AM – ~7:30–8:00 PM (orange flag until ~7 PM, some lines later).
Tips:

Boats can get extremely crowded in rush hours.
You pay on board (collector comes around).
Stand near the back or sides to avoid getting splashed when the boat docks.
The orange-flag boats are usually the best value for most tourists.


Smaller cross-river ferries
At many temples and piers, tiny shuttle ferries cross the river for 4–5 baht (e.g., Wat Arun ↔ Tha Tien, or Pak Kret ↔ Nonthaburi).


There are also many private long-tail boat tours and dinner cruises, but the orange-flag express boats are the real “river taxis” that locals use every day.
In short: The Chao Phraya is Bangkok’s lifeline, and the express boats are a fast, cheap, and fun way to see the city from the water. Highly recommended!