Navigation and Seamanship

4.2.5.1. Flag signaling

                    

          Signal flags are used to communicate the messages. A set of signal flags consists of twenty six alphabetical flags, ten numerical pennants, three substitutes and an answering pennant. There is also a signaling system called Semaphore which uses the position of the flags relative to a person to denote the letter. As a general rule only one hoist should be shown at a time. Each hoist or group of hoists should be kept flying until it has been answered by the receiving station. If the receiving station cannot clearly distinguish the signal made to it, if it can distinguish the signal but cannot understand the purpose of it, it can hoist the following signals.

          As a general rule only one hoist should be shown at a time. Each hoist or group of hoists should be kept flying until it has been answered by the receiving station. When more groups than one are shown on the same halyard they must be separated by a tack line. The transmitting station should always hoist the signal where it can be most easily seen by the receiving station, that is, in such a position that the flags will blow out clear and be free from smoke