Signalman 1 & C - Historic Naval Ships Association

A signal requiring the indication of position tocomplete its signification should be signaled asfollows:CH L2537N G4015W—Vessel indicated isreported as requiring assistance in lat. 25°37'Nlong. 40°15'W.DistanceFigures preceded by the letter R indicate distantin nautical miles.Example:OM A080 Rl0—Bearing and distance by radar ofvessel indicated are bearing 080°, distance 10miles.The letter R may be omitted if there is nopossibility of confusion.SpeedSpeed is indicated by figures preceded by1. the letter S to denote speed in knots, or2. the letter V to denote speed in kilometers perhour.Examples:TimeBQ S300—The speed of my aircraft in relation tothe surface of Earth is 300 knots.BQ V300—The speed of my aircraft in relation tothe surface of Earth is 300 kilometers per hour.Times are to be expressed in four figures, of whichthe first two denote the hour (from 00—midnight upto 23—11 p.m.), and the last two denote the minutes(from 00-59). The figures are preceded by1. the letter T, indicating local time, or2. the letter Z, indicating Greenwich mean time.Examples:BH T1045 L2015N G3840W C125—I sighted anaircraft at local time 1045 in lat. 20°15'N long.38°40'W flying on course 125°.RX Z0830—You should proceed at GMT 0830.Time of OriginThe time of origin may be added at the end of thetext. It should be given to the nearest minute andexpressed by four figures. Apart from indicating thetime a signal originated, it also serves as a convenientreference number.Communication by Local Signal CodesWhen a vessel or a coast station wishes to make asignal in a local code, the signal YV1—“The groupswhich follow are from the local code”—shouldprecede the local signal in order to avoidmisunderstanding.FLAG SIGNALINGA man-of-war desiring to communicate with amerchant vessel will hoist the CODE pennant in aconspicuous position and keep it flying during theentire time that signals are being made. This indicatesthat the signal groups are from the International Codeof Signals.Groups from the International Code of Signalsmay also be used between allied naval ships. They maybe used alone or to supplement basic signals from theAllied Maritime Tactical Signal and ManeuveringBook, ATP 1, volume II. Whenever military use ismade of the Code, groups will be preceded by CODEwhen transmitted by flaghoist, or INTERCO whentransmitted by Morse, voice, or hand flags. When onlyinternational signals are used, CODE/INTERCOfollowed by TACK are to be used as the first group toindicate that all of the following groups are taken fromthe Code. When used to supplement other signals,CODE/INTERCO immediately precedes the signalgroup to indicate that only the one group is taken fromthe Code. When using international signals tosupplement signals from ATP 1, volume II, or wheninternational signals are preceded by a naval callsign, naval procedure is used. Under all othercircumstances, international procedure is to be used.As a general rule, only one hoist should bedisplayed at a time. Each hoist or group of hoistsshould be kept flying until it has been answered by thereceiving station. When more than one group areshown on the same halyard, they must be separated bya tackline. The transmitting station should alwayshoist the signal where it can be most easily seen by thereceiving station; that is, in such a position that theflags will blow out clear and free from smoke.6-4