Signal flags are used to communicate messages to and from ships. These nylon outdoor flags are crafted from durable nylon material, with extra stitching for long-life usage in marine environments. The Size 0 flags with header and grommet are in stock and ready for immediate shipping; the rope and toggle variation is a made to order item with a lead time of 2-3 weeks. The alfa flag by itself indicates "I have a diver down; keep well clear at slow speed."