Naval Outlying Field San Nicolas Island or NOLF San Nicolas Island is a military airport located on San Nicolas Island, in Ventura County, California. The airport is administered by Naval Base Ventura County. The airport's ICAO identifier is KNSI. Although most U.S. airports and airbases use the same three-letter location identifier for the FAA and IATA, NOLF San Nicolas Island is assigned NSI by the FAA, The IATA has assigned NSI to Nsimalen International Airport in Yaoundé, Cameroon.