 From here, the river flows south and becomes the boundary between South Kingstown and Narragansett.The river continues to Pettaquamscutt Cove then out to Narragansett Bay.The Pettaquamscutt River is also commonly known as the Narrow River, both because of a long narrow stretch from Lacy bridge to the Mettatuxett Yacht Club as well as the narrow, hazardous mouth of the river where it empties into Narragansett Bay.