Waters within 200 nautical miles (370 km) of North America and the Hawaiian Archipelago—the Exclusive Economic Zone (EEZ)—are considered within North American boundaries by bird records committees (e.g., Erickson and Terrill 1996).
Seabirds within 370 km of the southern Hawaiian Islands (hereafter referred to as Hawaiian waters) were studied intensively by the Pacific Ocean Biological Survey Program (POBSP) over a 15-month period in 1964 and 1965 (King 1970). These researchers replicated a trackline each month, providing considerable information on the seasonal occurrence and distribution of seabirds in these waters.