Flight plans are ocuments filed by pilots or a Flight Dispatcher with the local Civil Aviation Authority (e.g. FAA in the USA) prior to departure. They generally include basic information such as departure and arrival points, estimated time en route, alternate airports in case of bad weather, type of flight (whether instrument flight rules or visual flight rules), pilot's name and number of people on board. In most countries, flight plans are required for flights under IFR. Under VFR, they are optional unless crossing national borders, however they are highly recommended, especially when flying over inhospitable areas, such as water, as they provide a way of alerting rescuers if the flight is overdue.