Boating Distress Signals

August 2, 2021

Whether you are a pleasure boater on a small craft or an experienced captain commanding a commercial vessel, it’s essential to be familiar with marine distress signals.

With that in mind, we decided to create a guide to visual, audio and radio distress signals.

Here are the most efficient ways to signal that your crew is in danger and recognize when another boat is in trouble and needs assistance.

Marine visual distress signals

Distress flags N over C


To signal distress, you can use the International Code of Signals. The International Signal for Distress is Code Flag ‘N’ flown above Code Flag ‘C’.

A ball over or under a square flag


This marine visual distress signal consists of a square flag accompanied by a ball or similarly-shaped object. The ball can be placed over or under the flag.

Orange distress cloth with a black square and circle


This distress signal is designed to be visible to planes and helicopters. It is a piece of orange cloth with a black square and a black circle on it.

Parachute flare


To signal that you need assistance while boating, you can send up a parachute flare. This type of flare creates a single red star that reaches a height of around 300 m (984 ft.), then floats down gently with the aid of a parachute. It can be seen easily from the ground or the air and burns for around 40 seconds.

Multi-star flare


A multi-star flare can also be used to signal distress while boating. It creates two or more red stars, which reach a height of around 100 m (328 ft.). They are easily visible from the ground or the air and burn for 4 or 5 seconds.

Hand flare


This distress signal is a red flame that burns at the end of a hand-held torch. The flame offers limited visibility from the ground, but is the best way to pinpoint your position from the air. It burns for around a minute.

Floating or hand-held orange smoke signal


This type of boating distress signal produces dense orange smoke for around 3 minutes and is most effective during the day.

Flames on the boat


Flames on a boat can be used to alert other vessels that the crew is in distress. You can use oil or other combustible materials to create flames, but be very careful to make sure they don’t get out of control.

Dye markers


During the day, you can release orange dye into the water to signal that you are in distress. This visual signal makes it much easier to spot your boat from the air.

Arm signals


You can also signal distress by placing your arms straight out to the sides and moving them up and down slowly and repeatedly. (Don’t do this near a helicopter, because the signal means something different to them.)

Marine audio distress signals

Gunshots or explosive sounds at one-minute intervals


Firing off gunshots or making explosive sounds at one-minute intervals signals that you are in distress on a boat.

Continuous sound from a foghorn, bell, whistle or other sound-signalling device


Continuous sound from a sound-signalling device will alert other boats that you are in trouble and need help.

Marine radio distress signals

SOS in Morse code (… —…)


If you have a device on board that allows you to communicate in Morse code, you can signal distress by transmitting an SOS.

Repeat “MAYDAY” over VHF radio


If you have a marine VHF radio on board and you need to send a distress signal (for example, if you boat is taking on water and you are in danger of sinking or capsizing due to a collision), use channel 16 and repeat “MAYDAY” 3 times. You must give the name of your boat, its position, the nature of your problem and the type of assistance you need.

Dial *16 on your cell phone


You can also use your cell phone to call for help and rescue by dialling *16. However, cell phones do not always work well on the water and should not be considered a substitute for VHF radio.

Emergency Position Indicating Radio Beacon (EPIRB)


If you have the equipment on board, an Emergency Position Indicating Radio Beacon (EPIRB) can be an effective way of signalling distress.

The NBSS: your resource for boating safety information

Remember that the boating distress signal you should use will depend on the time of day (day or night), weather conditions and the safety equipment you have on board.

Want to learn more about boating safety and recreational boating? The National Boating Safety School is your best resource. Our boating safety course is the ideal tool to help you prepare for the online boating exam, which is required in order to obtain your boating license (Pleasure Craft Operator Card).

Get your card today