As a delta region of the great Kaveri (Cauvery) River, Karaikal is intersected by multiple waterways before they empty into the sea.
* **Arasalar River:** The most prominent river flowing through the heart of the city. * **Kaveri Distributaries:** Other key rivers meandering through the district include the Nandalar, Nattar, Thirumalairajanar, and Pravadayanar. * **Bay of Bengal:** Forms the entire eastern border of the city, providing a long, scenic coastline.