The history of the Chao Phraya River and the city of Bangkok are deeply connected.
The city was founded precisely because of the conditions that this river provided to the founding inhabitants of the city. After the fall of the old capital, Ayutthaya, the king decided to found, where Bangkok stands today, the new capital of Thailand.
For a boat tour or to cross the river you can catch a boat from the Chao Phraya boat company, which operates daily between 6am and 7.30pm.
You can also opt for tourist offers, with tours starting from 9 ports, for 150 bath, between 9.30 and 15h. It is a good option if you want more comfort and accompany the views with a Chang beer. These boats depart every 30 minutes, unlike the previous ones departing every quarter hour.
Finally, if you are looking for something more personalized, hire a long tail boat for a river cruise with the possibility of including a meal.
Either way do not forget to take a boat trip, which will give you a unique perspective of the city.