The document discusses the proper use of various distress and urgency signals used in maritime mobile radio communications under the Global Maritime Distress and Safety System (GMDSS), including: - MAYDAY is used when a vessel is in grave and imminent danger and requires immediate assistance. - PAN PAN indicates a very urgent message concerning safety but not requiring immediate assistance. - SECURITE conveys an important navigational or meteorological warning. It also provides guidance on appropriate responses to urgency signals without a following message and situations where urgency messages can be transmitted on the working frequency.

1. GMDSS VASU 09841852069/09629980476 vasurc@gmail.com
When do use the following signals?
MAYDAY
When a mobile unit is in grave and imminent danger and it requires immediate
assistance
MAYDAY RELAY
When a station in distress itself not able to transmit its own distress call or message
When a master or the person responsible of a mobile unit not in distress
Or the person in charge of the land station feels further help is necessary
PAN PAN
A very urgent message concerning the safety of a mobile unit or safety of a person
Will follow
SECURITE
An important navigational warning or an important meteorological warning
SEELONCE MAYDAY
Imposing silence on the interfering station by the controlling station during distress
Traffic
SEELONCE DISTRESS
Imposing silence on the interfering station by the station other than the controlling
station during distress traffic
PRUDONCE
Distress traffic is still in force. Restricted working may be resumed. This is announced
by the controlling station.
SEELONCE FEENEE
Distress traffic is ceased. Normal working may be resumed. This is announced by the
controlling station on voice.
SILENCE FINI
Distress traffic is ceased. Normal working may be resumed. This is announced by the
controlling station on NBDP.

2. You have received urgency signal. No urgency message is followed. What action
will you take?
Wait for 5 minutes
If no message is followed,
Inform nearby CRS and resume working
On what situations, urgency message is transmitted on working frequency?
A long message or a medical message
A repeat of the message in the heavy radio traffic area
Safety message is broadcast at fixed times. Other than this, when the safety
messages can be transmitted?
On receipt of the message
At the end of next silence period
What radiotelephone signal should precede the following type of messages?
Vessel grounded in shallow waters and listing
MAYDAY
Oil rig movement
SECURITE
Vessel over due
PAN PAN
Request for medical advice
PAN PAN
Helicopter sighted crash landing in the sea
MAYDAY RELAY
Cyclone Warning
SECURITE
Repositioning of an Oil rig
SECURITE
A vessel having lost its propeller, requiring a tow
PAN PAN
Vessel sighting a floating mine
SECURITE
Vessel listing and in danger of sinking, requiring immediate assistance
MAYDAY
Vessel grounded in shallow waters
MAYDAY