Rio del Mar, California, United States [CDP]; population was 8,919 in 1990; housing units was 4,580 in 1990; location is 36°57'N 121°53'W; land area is 2.99 square miles (1,914 acres); water area is 1.63 square miles (1,040 acres); FIPS code is 60928 [SourceCBP]