Communications

VHF DSC radio – how best to communicate at sea

By on Nov 2, 2015 in Communications, Emergencies, Preparation | 0 comments

There are many ways to communicate with others at sea. What makes the VHF DSC radio the best form of short range communication and why is it recommended?   The controls of a basic VHF DSC radio There are many ways to communicate with others at sea, ranging from signal flags to satellite phones. While it is not a legal requirement in most countries, leisure vessels are strongly encouraged to use VHF DSC (Digital Selective Calling) radio as their primary means of communication, since this is used by the rescue authorities and commercial shipping.  VHF has a maximum range of up to about 30 nautical miles, but for ocean cruising SSB radio is the preferred option as it has a much better range than VHF. Is VHF DSC radio really necessary for inshore sailing? It is a mistake to believe that a mobile phone is all that is required for inshore sailing. Mobile phones are a useful back up means of communication but cannot be relied on, as even when close to the shore signal can easily be lost. VHF DSC radio features A VHF DSC radio allows users: to communicate with shore-based VHF users such as the Coastguard, harbour masters, lock-keepers and marinas to dial up other vessels by using a unique identity number to have one to one conversations with other vessels to send distress alerts at the touch of a button to automatically send your vessel’s identification number and position to others Operator’s licence Anyone who uses a VHF DSC radio must have an operator’s licence, the Short Range Certificate.  In an emergency, any crew member can use the radio, but it is advisable for those who sail regularly to do the one day course and get their own certificate, so that if for any reason the skipper is unable to use the radio, there are others aboard who know the correct radio procedure and can act quickly if the need arises. A VHF DSC radio that is linked to a vessel’s GPS shows its position on the display screen, as well as the current time Fixed radios vs handheld VHF DSC radios are available as fixed radios attached to a vessel or as handheld, personal...

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Know your Navlights & Shapes – essential for all skippers

By on Jul 17, 2015 in Communications, Navigation, Preparation | 0 comments

Know your Navlights & Shapes International Regulations for Preventing Collisions at Sea (ColRegs) Anyone who is responsible for a vessel at sea, from the smallest dinghy to an ocean going supertanker, day or night, must be able to recognise other vessels and quickly interpret what they see around them. This is not always easy, especially in crowded coastal waters. Rule 21(b) – “Sidelights” means a green light on the starboard side and a red light on the port side each showing an unbroken light over an arc of the horizon of 112.5 degrees and so fixed as to show the light from the right ahead to 22.5 degrees abaft the beam on its respective side. In a vessel of less than 20 metres in length the sidelights may be combined in one lantern carried on the fore and aft centreline of the vessel. Rule 23 – Power-driven vessels underway (a) A power-driven vessel underway shall exhibit: (i) a masthead light forward; (ii) a second masthead light abaft of and higher than the forward one; except that a vessel of less than 50 metres in length shall not be obliged to exhibit such light but may do so; (iii) sidelights; (iv) a sternlight. (b) An air-cushion vessel when operating in the non-displacement mode shall, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit an all-round flashing yellow light. (c) A WIG craft only when taking off, landing and in flight near the surface shall, in addition to the lights prescribed in paragraph (a) of this Rule, exhibit a high intensity all-round flashing red light. (d) (i)A power-driven vessel of less than 12 metres in length may in lieu of the lights prescribed in paragraph (a) of this Rule exhibit an all-round white light and sidelights; (ii) a power-driven vessel of less than 7 metres in length whose maximum speed does not exceed 7 knots may in lieu of the lights prescribed in paragraph (a) of this Rule exhibit an all-round white light and shall, if practicable, also exhibit sidelights; (iii) the masthead light or all-round white light on a power-driven vessel of less than 12 metres in length may be displaced from the fore and aft centre...

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Boating emergency – how to broadcast a MAYDAY emergency call

By on Mar 10, 2015 in Communications, Emergencies | 0 comments

How to broadcast a MAYDAY emergency call   How to broadcast a MAYDAY emergency call if a vessel or person is in grave and imminent danger and immediate assistance is required: • Check that your VHF radio is on and high power setting is selected Select Channel 16 (or 2182kHz for MF) • Press the transmit button and say slowly and clearly: “MAYDAY, MAYDAY, MAYDAY”“THIS IS… ” (say the name of your vessel 3 times. Say your MMSI number and call sign) “MAYDAY, THIS IS…” (say name of vessel) “MY POSITION IS…” (latitude and longitude, true bearing and distance from a known point, or general direction) “I AM…” (say nature of distress eg SINKING, ON FIRE) “I REQUIRE IMMEDIATE ASSISTANCE”“I HAVE…” (say number of persons on board PLUS any other useful information – such as sinking, flares fired, abandoning to liferaft) “OVER”• Now release transmit button and listen for reply • Keep listening to Channel 16 for instructions • If you hear nothing then repeat the distress call Vessels with GMDSS equipment should make aMAYDAY call by voice on Ch 16 or MF 2182 kHz after sending a DSC Distress alert on VHF Ch 70 or MF 2187.5 kHz  DSC Radio Emergency Procedure • In an emergency, press the DSC radio’s red button for 15 seconds and then transmit a voice message on Channel 16. • Prepare for sending/receiving subsequent distress traffic on the distress traffic frequency (2182 kHz on MF, Ch16 on VHF) • NOTE: The nature of distress can be selected from the DSC radio receiver’s menu. Information from our Safe Skipper App “A well written and detailed app for yachts & inland craft also quite useful for ocean going vessels – well...

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The VHF DSC Radio jargon buster

By on Sep 11, 2014 in Communications, Preparation | 0 comments

AIS – Automatic Identification System This system is used by shipping. It allows another vessel or coast station to use equipment that can interrogate the radio in order to learn the course, speed, type of vessel, cargo, etc. It is also available to recreational vessels. ALRS Admiralty List of Radio Signals ATIS Automatic Transmitter Identification System Authorised Operator The person with the VHF Short Range Certificate who also has an Authority to Operate. Callsign Unique letter/number vessel identification number CG66 Coastguard Yacht and Boat Safety Scheme form Convention ships Cargo vessels over 300 Gross Registered Tons and passenger ships that carry 13 or more people. COSPAS/SARSAT A satellite-aided search and rescue system designed to locate EPIRBS transmitting on 406 MHz. Distress A situation when a vessel, vehicle, aircraft or person is in grave and imminent danger and requests immediate assistance. DSC Digital Selective Calling DTI Department of Trade and Industry Dual watch A facility that allows you to monitor CH16 and one other channel at the same time. Duplex Radio working that uses two antennas for working on a two frequency VHF channel. EPIRB Emergency Position Indicating Radio Beacon GHz Gigahertz GMDSS Global Maritime Distress and Safety System GMT Greenwich Mean Time GPS Global Positioning System HF High Frequency IMO International Maritime Organisation INMARSAT International Mobile Satellite Organisation ITU International Telecommunication Union Mayday Distress signal. Origin French – m’aidez – help me. MF Medium Frequency MHz Megahertz MMSI 9-digit Maritime Mobile Service Identity Navtex Maritime safety information broadcast received on 518 KHz and 490kHz as text. NBDP Narrow Band Direct-Printing, see Navtex NMEA interface Marine industry standard method of connecting one piece of electronic equipment to another, eg GPS with autopilot. Pan Pan–Urgency signal. Origin French – en panne – in difficulty. PTT Press to transmit switch Public Correspondence Telephone communications Radio Check Test call that asks ‘What is the strength and clarity of my transmission?’. Radio horizon The distance the radio signal will travel before it reaches the horizon. RX Receive SAR Search and Rescue Securite Safety signal. Origin French – sécurité – safety. Semi-Duplex Radio working that uses one antenna to switch between two frequencies on one channel. One frequency for transmitting, the other for receiving. Simplex Radio working...

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