Royal Army College

Lesson Overview

The radio is not always the right tool, and sometimes it is the wrong one. A soldier on a careful patrol who keys a handset to say "stop" has made a noise that carries, put a signal on the air an adversary can hear, and taken longer than the moment allowed. Often the message is simple, instant, and silent: halt, take cover, threat to the front. For these the answer is a signal made with the hand, held together by a patrol that watches, repeats, and acknowledges. Silent signalling is not a fallback for when the radio fails; it is the everyday language of a patrol on the move.

This lesson teaches that language and the discipline that carries it: why silent signals matter for stealth, the standard field hand and arm signals, how one signal passes reliably down the length of a patrol, and the narrow agreed uses of whistle and torch. It then adds a wider standard a coastal force will meet, the International Code of Signals, the recognised international system for visual and sound signalling between vessels, stations, and services. Above all it presses the rule on which the whole system depends: every member must read and make the same signal the same way, agreed and rehearsed before a single step is taken, or the system fails. These signals hold together the drills of Patrolling and Tactical Movement and respect the noise and light discipline of Navigation and Fieldcraft.

As in the navigation lessons, this is the knowledge layer. Reading a fist at the edge of a wood and getting down without a sound, passing a signal cleanly down a moving line, working a torch by night without blinding the patrol or marking it: these are skills built on the ground and on the airsoft military-simulation field, and certified in person. Learn here what each signal means and how the discipline carries it, so that on the ground you already understand the language you are about to speak with your hands.

By the end you will be able to explain why silent signals matter and when they are preferred to the radio, describe and begin to make the standard field hand and arm signals, explain the discipline of watching and passing a signal so one signal reaches everyone, describe the agreed uses and risks of whistle and light signals, recognise the key single-letter signals of the International Code of Signals and say where that code fits for a force with a coast, and explain why standardisation is the rule on which silent signalling stands or falls.

Key Terms

Hand and arm signal: a silent message made with the hand, arm, or weapon to a standard meaning, used to pass orders and warnings without speaking.
Noise and light discipline: the deliberate control of every sound and glimmer a patrol produces, so it is neither heard nor seen before it chooses to be.
Passing a signal: the drill by which each soldier sees a signal from the soldier ahead, makes it clearly to the next, and so carries one message along the whole patrol.
Acknowledgement: the return signal confirming a message has been seen and understood, the silent equivalent of readback on the radio.
Rally signal: a prearranged whistle blast or other cue that calls a patrol to a known action or place, such as rallying after a contact.
Standardisation: the agreement that everyone makes and reads each signal in exactly the same way, settled and rehearsed before moving so meaning never depends on guessing.
International Code of Signals: the recognised international system for communication between vessels and stations, by which a letter or short group carries a standard meaning understood across languages and services; it may be sent by flag hoist, by flashing light in Morse, by sound, or by voice.
Single-letter signal: a signal in the International Code made of one letter, reserved for the most urgent and common meanings, which every member of a coastal force should recognise on sight or by sound.

Why Silent Signals Matter

A patrol's first protection is that it is not seen or heard until it chooses to be, and the radio works against that protection. A transmission is a sound made and a signal sent into the air; both can betray a patrol's presence, and sometimes its rough position, to anyone listening or watching. Sometimes the cost of speaking is simply too high: when stealth is the whole point of the task, when a careless word on the net would undo an hour of careful movement, or when the situation is too close to say anything at all. In all of these the silent signal is not second best. It is the correct tool.

Silent signals also win on speed when speed is everything. A threat seen at the edge of a wood line must be passed in the instant it is seen, before a soldier walks into the open. A clenched fist raised at once does the work, and every eye that catches it understands, where there is no time to compose a message, key a handset, and wait. The hand signal also lets a commander adjust spacing, change direction, or call a halt without breaking the rhythm of the move, where reaching for a handset stops the patrol's hands and eyes for the seconds it takes to speak.

And silent signals keep working when the radio does not. Sets fail, batteries die, and ground swallows a signal; a patrol that can talk only by radio is mute the moment the radio is gone, while a patrol fluent in hand signals carries on. When the net dies, the patrol does not stop thinking; it changes language. So the hand signal, not the handset, is the routine means by which a moving patrol passes simple orders and warnings, and the radio is reserved for the message that genuinely needs it, the report that must reach a station the eye cannot.

The Standard Field Hand and Arm Signals

Because these signals are visual, you must be able to picture each one and make it cleanly. Learn them by doing them, slowly and exactly, until meaning and movement are one. A signal made halfway, or made differently each time, is worse than none. Make a signal large enough to be seen and held long enough to be caught, but no larger than it must be, because a wild gesture is itself a give-away; make it against a background that shows your hand, not against the sky where the patrol is skylined; and make it deliberately, so the soldier behind reads a clear word and not a twitch. The common signals are these.

Halt or stop. The arm is raised, hand open and held still at shoulder height or above. Everyone stops at once and holds position. A clenched fist is also widely used for halt; whichever your patrol agrees, use only that one. A hand that drifts back down too soon may be missed by the soldier still bringing their eyes up.
Freeze (do not move). A more urgent stop, often a sudden flat hand thrust up or held rigidly still, meaning stay absolutely motionless and silent this instant, mid-stride if need be. Movement, not shape, betrays a soldier: a still figure in dappled light is hard to pick out, while the same figure taking one more step draws the eye at once.
Advance or move forward. The arm swings forward in the direction of travel, beckoning the patrol on. The same motion points the way the patrol is to go, so it doubles as a direction.
Close up. The hand or arm gestures inward, drawing soldiers nearer together, used when ground or poor light makes wide spacing unworkable, as when a patrol enters thick cover or darkness and must come close enough to keep each other in view.
Extend or spread out. The arms open outward, signalling soldiers to increase the distance between them, so that one burst or one mishap cannot catch more than one soldier.
Go firm or take cover. A flat hand pressed downward toward the ground tells the patrol to get down, take cover, and hold. It is the instinctive response to sudden danger and the prelude to all-round defence; soldiers drop, find what cover is to hand, and turn outward to watch their arcs.
Enemy or possible threat seen. A deliberate, controlled signal, never a panicked one, indicating a threat has been seen, with the hand or weapon then pointing slowly in its direction so everyone learns where to look. A slow, low point that follows the line of sight tells the patrol where the threat lies without throwing an arm into the air for the threat to see in return.
Obstacle or danger area ahead. An agreed signal warning of a hazard to the front, a fence, a track to be crossed, an open stretch, so the patrol approaches it ready and deliberate. The warning travels ahead of the hazard, so each soldier meets the danger already knowing it is there.
Come to me, or commander wants you. The hand beckons a named soldier or the whole patrol toward the signaller. Indicating who is wanted first, by pointing, then beckoning, saves the wrong soldier moving and the right one staying put.
Message understood (acknowledge). A clear return signal, such as a thumbs-up or a nod where it can be seen, confirming the message has been seen and understood. This is the silent readback, and no signal is complete without it.
Casualty. An agreed signal indicating someone is hurt and help is needed, so the patrol can react and prepare to pass a casualty report once it is safe to do so.
Ammunition or supply. An agreed signal indicating a need for ammunition or other supply, so a soldier running low can say so without breaking silence.

A clean quick-reference list helps fix the core signals in memory. Keep one like this in your notebook, in your patrol's agreed form, and study it until shape and meaning come together without thought.

FIELD HAND SIGNALS (QUICK REFERENCE)

"Halt / Stop":          open hand or fist raised, held still
"Freeze":               flat hand thrust up; do not move at all
"Advance / Move":       arm swung forward in direction of travel
"Close up":             hand drawn inward; come together
"Extend / Spread out":  arms opened outward; increase spacing
"Go firm / Take cover": flat hand pressed down toward the ground
"Enemy / Threat seen":  controlled signal, then point slowly to it
"Obstacle / Danger":    agreed warning of a hazard to the front
"Come to me":           beckon the soldier(s) toward the signaller
"Understood":           thumbs-up or clear nod; acknowledge
"Casualty":             agreed signal; someone is hurt
"Ammunition / Supply":  agreed signal; resupply needed

Passing Signals Down the Patrol

A hand signal is only as good as its reach, and on a patrol strung out across ground, no single soldier can see everyone. The signal therefore travels, by a drill every soldier owes the patrol. Each soldier watches the soldier ahead; when a signal comes, they make it clearly to the next soldier down the line, and so one message moves from the commander to the last person without a word. A soldier who is not watching is a broken link, and the signal stops at them.

Picture the drill on a single line of soldiers, the simplest case. The commander up front makes the signal; the second soldier catches it, turns far enough to be seen, and remakes it for the third; the third does the same for the fourth, and so on to the rear. The signal travels in one direction, front to rear, like a word passed mouth to mouth, and each soldier is both reader and sender in turn.

PASSING A SIGNAL DOWN A PATROL

  Commander            #2            #3            #4 (rear)
     [O] --signal--> [O] --signal--> [O] --signal--> [O]
                                                       |
     [O] <---ack---- [O] <---ack---- [O] <----ack-----+

  Each soldier watches the one AHEAD, remakes the signal
  for the one BEHIND, then the acknowledgement runs back
  front <- rear so the commander knows all received it.

Acknowledgement closes the loop, just as readback does on the radio. When the signal has run its length and been understood, the acknowledgement is passed back so the commander knows the patrol has received it. A signal sent and never confirmed is a hope, not a communication; a commander who orders a halt and sees no acknowledgement must assume the rear is still moving. The chain breaks in a few honest ways, and knowing them helps you guard against each: a soldier looking at their feet instead of ahead, a signal made too small or too fast to catch, a signal made against the skyline so its shape is lost, or a soldier who receives but forgets to pass on. Pass every signal on faithfully, acknowledge every signal you receive, and watch the soldier ahead as a duty. If a signal reaches you that you do not understand, do not guess and do not pass on a guess; make the agreed query signal back up the line and have it sent again, exactly as you would say "say again" on the net rather than act on half a message. Done well, this drill lets a patrol change formation, take cover, or react to a threat as one body, silently, which is what the drills of Patrolling and Tactical Movement depend upon.

Whistle and Light Signals

The whistle and the torch extend silent communication where the hand cannot reach, by night or across distance, but both carry a sharp cost and so are used narrowly and only as prearranged. A whistle blast travels far and fast, which is its value and its danger. It can deliver a prearranged warning or act as a rally call, gathering a patrol to a known action after a contact when hand signals can no longer hold it together; but the same blast tells anyone within earshot that you are there and roughly where. So the whistle is reserved for the few meanings agreed beforehand, blown only when the warning or rally is worth the noise, never as idle signalling. Its code must be short and unmistakable: a force will usually agree no more than two or three distinct blasts, for example a single long blast for one prearranged action and a succession of short blasts for another, each settled and written down before the patrol moves so that no soldier has to count under pressure and guess.

Light or torch signals serve the same narrow purpose at night. A brief, shielded flash, or a short agreed sequence, can pass a prearranged meaning when a hand signal cannot be seen: a recognition signal between elements, a simple yes or no, a marker showing a position or a find. But light at night is a beacon. White light destroys a soldier's night vision for many minutes and is visible far further than the user imagines, so every torch signal must be controlled with strict light discipline: shielded and filtered where authorised, aimed only where it must go, never up into the air or back toward the patrol, used in the shortest possible burst, and never swept carelessly. As with the whistle, the meanings must be few and fixed; one flash and two flashes can stand for two clear, prearranged messages, but a torch worked at length becomes a sentence no one has agreed and a light everyone can see. An unplanned blast or flash means nothing to the patrol and something useful to an adversary. This is the noise and light discipline of Navigation and Fieldcraft applied to signalling: every signal you make must be weighed against what it gives away.

The International Code of Signals

The hand, the whistle, and the torch are the patrol's own private language, agreed within the section and meaningful only to those who rehearsed it. There is also a public language, recognised across the world, for the moment a small force must signal to people who never sat in its orders group: another vessel, a harbour station, a lifeboat, an allied ship. That language is the International Code of Signals, the recognised international standard for visual and sound signalling at sea and along the coast. Its purpose is to carry essential messages across the barrier of language: a station that knows the code can read a signal whatever tongue the sender speaks, because the meaning is fixed to the letter, not to any one language. For a small force with a coastline, working its own waters and sometimes alongside the civil rescue service or an allied ship, this is the maritime counterpart to the phonetic alphabet and the map symbols.

The code is built to be sent by whatever means the situation allows, and the same meaning carries through every channel. It can be sent by flag hoist, raising the code's coloured flags on a halyard where another vessel can read them; by flashing light in Morse, the letters spelled out in long and short flashes, the method most useful to a small shore party with a signalling lamp; by sound, the same letters made as long and short blasts on a whistle, horn, or siren when fog or distance hides a light; and by voice, spoken over a loud-hailer or a radio using the phonetic alphabet, each letter named in full. The discipline you have already learned carries straight across: keep the message short, send it clearly, and have the receiver confirm it, exactly as on the net.

The heart of the code, and the part every member of a coastal force should know, is the set of single-letter signals. These are the most urgent and most common meanings, each given a single letter so it can be sent fast and read at once, by flag, light, sound, or voice. You are not expected to carry the whole code in your head; you are expected to recognise this short, usable set on sight and by sound, the way you recognise a fist or a flat hand pressed down. Learn them as a small vocabulary, the maritime equivalent of the core hand signals, and confirm the current meanings against the published code before you rely on them, because the code is the authority just as the map's legend is.

INTERNATIONAL CODE OF SIGNALS: KEY SINGLE-LETTER SIGNALS
(phonetic name in brackets; meaning to recognise on sight or by sound)

   A  (Alfa)     "I have a diver down; keep well clear at slow speed."
   O  (Oscar)    "Man overboard."
   V  (Victor)   "I require assistance."
   W  (Whiskey)  "I require medical assistance."

   DISTRESS (the recognised two-flag call):
   N over C  (November-Charlie)  "I am in distress and require
                                  immediate assistance."

   Send by flag hoist, by flashing light in Morse,
   by sound (long/short blasts), or by voice (phonetic).
   The meaning is fixed to the letter, not to any language.

Read the set with the eye of a soldier, not a sailor, and its value is plain. A diver down means a hazard in the water to keep clear of; man overboard and the two calls for assistance and for medical assistance are exactly the messages a small force on the water most needs to send or read in a hurry; and the distress signal, the two flags November and Charlie shown together, is the recognised maritime cry for help, the counterpart to the distress conventions taught for the land in Navigation and Fieldcraft Lesson 09. That lesson teaches how the lost and stranded make themselves found, and names the International Code of Signals as the maritime equivalent that sits alongside the ground-to-air signals; this lesson gives you the working core of that code. Where a hand signal holds a patrol together in silence, the International Code lets that same patrol speak, across water and across language, to the wider service it may have to work beside. Treat it as you treat every signal in this lesson: agreed, recognised, and confirmed, never guessed.

Why Standardisation Is Everything

A signal carries meaning only because sender and receiver have agreed what it means, and the moment that agreement is missing, the signal is noise. A clenched fist that means halt to one soldier and freeze to another will get a patrol moving when it should be still. A signal one soldier invents and never teaches is, as the Basic Training Manual puts it, worse than no signal at all, because it invites a confident, wrong response. The same truth runs through every layer of this lesson: the hand signals work only because the patrol agreed them, the whistle and torch codes work only because their few meanings were fixed beforehand, and the International Code of Signals works across the world only because every maritime service has agreed the same meaning to the same letter. Standardisation is not a refinement of the system; it is the system.

This is why signals are settled and rehearsed before a patrol steps off, not improvised on the move. The commander confirms which signals will be used, including the few whistle and light signals and any particular to the task, and the patrol practises them until every soldier gives and recognises each one without thought. Rehearse them above all on the airsoft military-simulation field, under the Airsoft Milsim Safety and Conduct Standard, where a patrol must hold itself together silently under mild, safe pressure and a missed or misread signal shows up at once: a halt that half the patrol misses, an enemy signal made too late, a torch worked too long. Practise until the signal and its meaning are fixed below conscious thought, so that under pressure a soldier reacts as rehearsed. A patrol that has done this work moves and reacts as one; a patrol that has not is a collection of people guessing at each other's hands.

In Practice: A Night Cordon After a Storm at a Coastal Cove

A coastal track running into a small cove has flooded after a storm and a farmstead is cut off, with a report of someone unaccounted for. An RKA section moves in by night to search the outbuildings and field margins, working close to civilian homes, so noise and light are kept down throughout. Before stepping off, the section commander confirms the hand signals to be used and two agreed torch signals: a single shielded flash for "found, come to me", a double flash for "all clear, move on". Because a civil rescue boat is standing offshore to lift the resident if the track stays cut, the commander also confirms the single-letter signals the section will use to talk to it: V by shielded light if the section needs assistance brought ashore, W if there is a medical case to lift. On the approach the lead soldier raises a still open hand; the halt is passed down the section and acknowledged back, soldier by soldier, until the commander knows everyone has stopped. A flat hand presses downward and the section goes firm as a vehicle's lights sweep the track; nobody moves until the lights pass, because movement, not shape, betrays them. When the lead soldier finds the missing resident sheltering in a barn, hurt but alive, there is no shout and no careless transmission: one shielded flash brings the commander forward, the casualty signal readies the section to help, and a slow W flashed seaward in Morse tells the waiting boat a medical lift is needed, the meaning fixed to the letter so the crew read it whatever the commander's accent. Only once the resident is safe and the situation calm does the section pass a quiet casualty report up the net. The search holds together in the dark, silently, because every signal was agreed and rehearsed before the first step, every soldier watched the one ahead, and even the message across the water used a code both sides already shared.

Check Your Understanding

Give two distinct reasons a patrol on the move would choose a hand signal over the radio. What does a radio transmission risk giving away that a silent signal does not, and why does a hand signal often suit an ordinary change of formation even when the radio would work?
Describe the drill for passing a signal down a patrol, including what each soldier watches and what they do with a signal they receive. What is the role of acknowledgement, to what radio habit does it correspond, and what should you do if a signal reaches you that you cannot read?
The International Code of Signals is a public, international standard rather than a patrol's private code. By what four means can a signal in the code be sent, and why does the same letter mean the same thing whatever language the sender speaks? Give the meaning of any two single-letter signals from the key set and the meaning of the N-over-C distress signal. Why is standardisation described as the system itself, across hand signals, whistle and torch codes, and the International Code alike, rather than a refinement of it?

Reflection (write a short paragraph): A silent patrol trusts every member to watch, to pass on, and to acknowledge faithfully, without a word to chase them. Think about your own place in that line. The soldier ahead has to rely on you to catch their signal and carry it on, and the commander has to rely on you to confirm you have understood. What does it mean for the patrol's safety that one soldier who looks away, or who makes a signal sloppily, can break a message meant for everyone, and what standard of watching, signalling, and acknowledging will you hold yourself to so that the silence around you stays a strength and never a gap?

Summary

Silent signals are the everyday language of a patrol on the move, not a fallback. They protect stealth and noise discipline, pass an instant warning faster than the radio could, suit ordinary changes of formation without breaking the move, and keep working when the radio cannot or should not be used.
The standard field hand and arm signals, halt, freeze, advance, close up, extend, go firm or take cover, enemy or threat seen with its direction, obstacle or danger ahead, come to me, message understood, casualty, and ammunition or supply, must be learned by doing until each is made cleanly, sized and placed to be read, and recognised instantly.
A single signal reaches the whole patrol only through discipline: each soldier watches the one ahead, makes the signal clearly to the next, and passes acknowledgement back, the silent equivalent of readback. One soldier who looks away breaks the chain, and a signal you cannot read is queried, never guessed.
The whistle and the torch extend signalling by night and across distance but reveal the patrol, so they carry only a few prearranged meanings, are used in the shortest controlled bursts, and obey strict noise and light discipline.
The International Code of Signals is the recognised international standard for visual and sound signalling at sea, sent by flag hoist, by flashing light in Morse, by sound, or by voice, with single-letter signals (such as A diver down, O man overboard, V require assistance, W require medical assistance) and the N-over-C distress signal that every member of a force with a coast should recognise; it is the maritime counterpart to the ground-to-air signals of Navigation and Fieldcraft Lesson 09.
Standardisation is the system itself, from the patrol's own hand signals to the world's shared maritime code: everyone must make and read each signal the same way, agreed and rehearsed before moving, above all on the airsoft military-simulation field, or the signals become noise and the patrol is left guessing.

Field Signals: Hand, Whistle, and Light