Last name สายน้ำ (River 
, Sainam 
, Sahip 
) , in the entire world, is a common cognomen. The family name สายน้ำ is characteristic of Marshall Islands, where it is quite a common surname, El Salvador, where it is quite a rare surname, and Puerto Rico. Measured by absolute frequency, the name is most common in India, Indonesia, and the United States. Also, สายน้ำ is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| River | China, Indonesia, United States, Myanmar, India |
| Sainam | Indonesia, United States, Malaysia, Thailand, India |
| Sahip | Indonesia, United States, Mexico, Malaysia, India |