Active Contributor Join Date Aug 2012 Posts 22 08/27/2012 431 AM I have a question regarding the GMDSS system mounted on Vessels or MODU. Why we dont have a combined unit that have both functionality of the EPIRB and SART, ie, we can send out the position signal where the distress was happened, in the meantime we could respond to Rescue Radar of the searching signal? Register to Reply Interested in this topic? By joining CR4 you can "subscribe" to this discussion and receive notification when new comments are added. Interested in this topic? By joining CR4 you can "subscribe" to this discussion and receive notification when new comments are added.EQUIPOSEPIRB Y SART ASI COMO LA COMUNICACION ENTRE EMBARCACIONES DE SALVAMENTO QUE ES EL EPIRB EPIRB Una radiobaliza de emergencia es un aparato transmisor de radio utilizado en situaciones de emergencia para facilitar la localización de un barco, un avión o una persona que se SART or Search and Rescue Transponder is extremely vital equipment on the ship as it performs the job of a signal-man. It is a vital machine during distress for it helps in locating the position of the vessel in case it goes off-track. SARTs are made of waterproof components which protects them against damage by water. SARTs are essentially battery-operated, hence can be operative for a long time. SARTs are of use in ships, lifeboats and liferafts. They are the most supportive machines in case of an unprecedented emergency. SARTs are designed to remain afloat on the water for a long time in case the vessel finds itself submerged in water. The bright colour of SARTs enables their quick detection, whereas the combination of transmitter and receiver enables it to transmit as well as receive radio signals. SART machines have been instrumental in rescuing several crafts and ships by reacting to the search signal sent from an X-band radar, typically of 9 GHz. These signals are known as homing signals. The response is usually displayed on radar screens as a sequence of dots on an X band-radar, which helps rescuers reach the vessels in time. Watch video on SART As mentioned earlier, SART is basically an electronic device that automatically reacts to the emission or interrogation by radar. This enhances the visibility of the party in need of assistance on the radar display PPI. They operate on the 9 GHz band and only transmit when they are switched on when interrogated by radar. SART – General features, location and functioning SART is made of fibre-reinforced plastic which can withstand and bear the prolonged exposure to sunlight and extreme weather conditions It is capable of floating free of the survival craft International orange in colour SART is mounted on a mounting bracket which is fixed to a bulkhead on a ship, on the bridge It operates on the 9GHz frequency band to GHz and generates a series of clips on the radar it is interrogated by 3 cm/X Band radar. They can either be portable or fixed permanently into the survival craft The SART is activated manually and hence responds only when interrogated When activated in a distress situation, the SART responds to radar interrogation by transmitting a signal which generates 12 blips on the radar and turns into concentric circles as the range between the two reduces On the PPI, the distance between the blips will be miles This signal is very easy to spot than a signal echo from say, a radar reflector The SART also has an audio or visual indication of its correct operation and informs survivors when interrogated by the radar An audible beep is heard every 12 seconds when there are no radars in sight and every 2 seconds when interrogated by radar Carriage Requirement Passenger ship- at least 02 Cargo ship 500 GT and above- at least 02 Cargo ship 300 GT and above- at least 01 1 on each survival craft Battery Requirement In standby condition, operational for 96 hours In working condition, operational for 08 hours Battery should be replaced every 2 to 5 years Operable in temperature between -20 deg to 55 deg SART Test Procedure Self Test General Switch SART to test mode Hold SART in view of the radar antenna Check that visual indicator light operates Check that audible beeper operates Observe radar display and see if there are concentric circles on the PPI Check the battery expiry date Self Test Typical Remove SART from the bracket Insert the probe into the SART at 2 seconds interval; the lamp flashes and the beeper sounds Observe concentric circles on the X band radar In case of a false activation, switch the SART off immediately. Transmit a DSC safety alert on VHF Channel 70. Transmit a safety broadcast by RT on VHF Channel 16 to all stations indicating your ID and position and that you wish to cancel your false alert which was transmitted in error. AIS-SART The AIS-SART is a self-contained radio device used to locate a survival craft or distressed vessel by sending updated position reports using a standard Automatic Identification System class-A position report. The position and time synchronization of the AIS-SART is derived from a built-in GNSS receiver GPS. Global Maritime Distress Safety System GMDSS installations include one or more search and rescue locating devices. These devices may be either an AIS-SART AIS Search and Rescue Transmitter or a radar-SART Search and Rescue Transponder. SARTs find themselves useful in rescue operations involving aeroplanes or ships stranded by air and sea accidents. They are designed to survive the toughest conditions and stay active on elevated positions like on a pole so that they could cover a diverse range. Talking of heights, a SART transponder on an aeroplane could have a range of 30 to 40 miles. This helps to scrutinize a huge range and huge area. Looking at the facts, one can determine that SARTs are a marvel of human engineering, making them significant equipments on the ship venturing out in deep oceans. You might also like to read Safety of Life at Sea SOLAS The Ultimate Guide Introduction to Global Maritime Distress Safety System GMDSS What You Must Know Daily, Monthly And Weekly Tests Of GMDSS Equipment On Board Ships Liferafts SOLAS Requirements, Safety Features, Launching Procedure Watertight Doors on Ships Types, Drills, Maintenance, SOLAS Regulations 5 Methods Of Medevac at Sea Shilavadra Bhattacharjee is a shipbroker with a background in commercial operations after having sailed onboard as a Third Officer. His interests primarily lie in the energy sector, books and travelling. Related Posts
AISSART, unlike a PLB or EPIRB, is a short range VHF transmission. AIS message type 14 (see https: When your AIS SART triggers in the water, every boat on the race course (in your scenario) with AIS (receive only or transponder) will alarm. Now if your club has their head screwed on right they have AIS on the committee boat.
As an Amazon Associate, Casual Navigation earns from qualifying and SARTs are both used to indicate your position in an emergency when you need rescuing at sea. The main difference between them is that they are used at different points of the rescue process because they are designed to communicate with different communicate with satellites and are used at the start of a rescue when you first alert emergency services to your location. SARTs communicate with other vessels and are used when rescuers are on scene and homing in on your exact are the main differences between an EPIRB and a SART?EPIRBs and SARTs are different pieces of safety equipment, designed for completely different purposes. I have summarised the differences in the table below, and you can read on for more bySAR authoritiesOther vesselsRescue stageInitialFinalGPSYesNoRangeUnlimited12 NMBattery life48h96h +12hPrice$500+Around $500Table showing the main differences between EPRIBs and SARTsWho receives signals from EPIRBs and SARTs?The most fundamental difference between EPIRBs and SARTs is in who they communicate Emergency Position Indicating Radio Beacons communicate directly with international search and rescue coordinators. In the initial stages of a rescue, they send your GPS location to satellites which relay it onto authorities Search and Rescue Transponders communicate with other vessels. They are used during the final stages of a rescue when a responding vessel is trying to locate the vessel in distress. It paints a distinctive pattern on a radar screen so that the responding vessel can home in on your exact EPIRBs and SARTs have GPS integration?EPIRBs are commonly equipped with GPS, giving them the ability to broadcast their location for satellites to receive. Older style EPIRBs did not use GPS, but orbiting satellites were able to triangulate its position type of EPIRB you have, the principle is the same. The signal from the EPIRB contains the position of the vessel in are different because they do not have GPS fitted. Instead, they are only useful when another vessel is close enough to detect the SART on its recent years, AIS SARTs have started to become more common. This sort of SART does get a GPS position, which is transmitted within an AIS signal. They still communicate with responding vessels though, as the range of AIS is limited by the height of the SART. Instead of painting a pattern on a radar, AIS SARTs plant an AIS target on the screen is the detection range of EPIRBs and SARTs?EPIRBs are detected worldwide. They depend on a network of satellites in different orbits, together covering the entire surface of the globe. Assuming there is a clear line of sight up to the satellites, EPIRBs can be detected are different because they are designed to be detected by other vessels in the immediate vicinity. Radar SARTs can be detected by any vessel fitted with an X-band radar. AIS SARTs can be detected by any vessel fitted with an AIS commercial vessels use their radar on a maximum range of 12 nautical miles. Some will have a second radar on a 24 nautical mile range when navigating in open areas. This means that a radar SART is only useful when another vessel is within either 12 or 24 miles, depending on the radar setting of the other range of AIS SARTs depends on the height of the antenna and atmospheric conditions. It is safe to assume that a properly mounted AIS SART can be detected within a similar range to a radar SART is the battery life of EPIRBs and SARTs?EPIRBs and SARTs both have legal requirements for the length of time their battery should minimum battery life for an EPIRB is 48h. This is the minimum transmission time that you can expect. Once you activate the EPIRB, search and rescue services have 48h of transmission time to deploy assets to your location. After that, the EPIRB could continue operating, but there is no search and rescue services will reach your position within 48h. Should it take longer, they can still work off of your last known position and deploy assets to the correct are designed to last longer than EPIRBs. In their resting state, you will have 96h of standby time. This means that the SART is listening out for radar signals in the area. Once the SART detects a radar in the vicinity, it switched into transmission transmission mode, a SART will last for a minimum of 12h. Transmission mode is used when vessels are close to your location. Vessels with operational radars should easily be able to reach your position within 12h once they are within radar SARTs, you can expect 96h standby time + 12h transmission time in does the price of EPIRBs and SARTs compare?Both SARTs and EPIRBs are comparable in price. Standard prices for both are around $ 1 EPIRBs may cost more due to the additional cost of their float-free arrangements. For a fair comparison between EPRIBs and SARTs, however, it is better to compare a SART to a Category 2 EPIRB because both need to be activated find the fairest comparison is between the ACR GlobalFix V4 EPIRB link to Amazon, and the ACR Pathfinder Pro SART link to Amazon. For accurate pricing, you can check out both links which will open in a new of buying an EPIRB, you could consider buying a PLB. PLBs are similar, but not identical to EPIRBs. You can read more about the differences between EPIRBs and PLBs in this article What Is The Difference Between An EPRIB And A PLB?If you did decide to buy a PLB instead, you can get similar functionality for a much lower price. Typical PLBs start at around $200, compared to nearer $500 that you would expect for an happens when you activate an EPIRB?After activation, Category 1 and Category 2 EPIRBs perform the same. Category 1 has the potential to activate automatically, and Category 2 is manual activation way, once you activate the EPRIB, it starts to transmit a signal on 406 MHz to the COSPAS SARSAT constellation of constellation consists of lots of satellites in different orbits. There are 5 in a low polar orbit, 10 in geostationary orbit, and over 40 others in medium altitude orbits. The goal is that the combined footprint from the satellites covers the entire surface of the EPRIBs have built in GPS, so part of the signal they transmit includes their GPS position. Older ones do not have GPS, so when the satellites pick up the signal they triangulate it over a couple of of the method of finding the position, the constellation of satellites now has the identification and position of the EPIRB that has been activated. It then sends that data down to control control stations determine the nationality of the EPRIB from its identity, and then forward the distress signal on to the appropriate national Maritime Rescue Coordination Center MRCC.Once the identity and position is received by an MRCC, they compare the identification number of the EPIRB to their database. This gives them additional information about the vessel in distress which they can use to attempt contact with the vessel or its then begin the process of searching for the vessel in distress and rescuing those on about how EPIRBs workWhat happens when you activate a SART?SARTs should be activated when you are in your survival craft, with the intention of drawing the attention of other you turn it on, it is in “listening mode”. In this mode, it is waiting to detect a pulse from an X-band 3cm wavelength radar. As discussed previously, there will be enough battery power to operate in “listening mode” for at least the SART detects a pulse from an X-band radar, it immediately switches into transmission transmission mode, the SART instantly returns a series of 12 pulses back to the radar. The time difference between the 12 pulses means that the SART appears as a series of 12 echoes on a radar this image you can see what a SART looks like on a radar searching vessel knows that the real location of the SART is on the echo closest to them, so they can plot a course to they get closer, the side lobes from the radar start to stretch the dots out to become wider. Eventually less than 1 nautical miles from the SART, the 12 dots become almost full circles. The vessel then knows that the SART is close and they should be able to see any survival craft showing you how a SART worksWhat happens when you activate an AIS SART?With AIS SARTs, it is a little different. Once it is activated, it searches for GPS satellites to determine its then broadcasts its own position and identity just like any other AIS device in the area will then see the AIS SART as a target on their navigation systems. They can use the position to plot an intercept course and rescue with any is an EPIRB better than a SART?EPIRBs are better than SARTs when there are no other vessels you have an emergency, the EPIRB broadcasts your distress to the network of satellites, which can be reached from any location on means that EPIRBs are especially useful when you are in a remote area like out at sea, or in an area that is infrequently navigated by other a different perspective, EPIRBs are also better than SARTs during the early stages of a rescue. Their signal should be sent to national Maritime Rescue Coordination Centers, who can activate sufficient resources for a successful is a SART better than an EPIRB?SARTs are better than EPIRBs when there are other vessels around that are equipped with operational x-band most common example is during the final stages of a rescue. Once other vessels arrive in the vicinity, a SART enables them to quickly find the people in vessels cannot directly detect the signal from an EPIRB, so the positional data would need to be relayed to responding vessels by the rescue coordinator. SARTs bypass that and give out signals that the other vessels can addition to that, the battery life of an EPIRB means that it could have expired before rescuers arrive on scene. In the middle of the Pacific ocean, the 48h battery life may not be enough for it to be operational by the time help example of when a SART could be better than an EPIRB is when you are navigating in a busy shipping area. The density of traffic means that the distress signal from the SART is likely to be picked up and acted upon this sort of situation, it is good if other vessels can see your distress themselves instead of waiting for a relayed signal from the SARTs are better than EPIRBs, in situations where there are other vessels around that are likely to detect the SART I carry an EPIRB or a SART on my boat?Unless you are legally required to carry an EPRIB or a SART, the choice of which you carry is up to and SARTs are both recognised as distress signals under the International Regulations for Preventing Collisions at Sea. The use of either one will mean that anyone detecting your signal should come and both is an ideal scenario, but clearly there are cost implications for doing so. At around $500 each, you are looking at over $1000 for I was to pick between them, I would choose to carry an reason I have chosen an EPIRB is that it should work in all situations, regardless of whether there are other vessels around or not. The direct satellite link, onwards to national maritime rescue centers just seems like the better understand that it means other vessels will not be able to respond as quickly as they could with a SART, but there are other options for that my boat I like to always carry flares, and I always have a VHF onboard as well. Both of these can be used to alert vessels in the vicinity if I ever have an the EPIRB needed to be activated, I would hope the position would be good enough to get other vessels close to me. After that, I would rely on my handheld VHF or flares to get their attention. Theidea of this project is to combine the SART and the EPRIB. There are several problems that will be addressed in this report. The main goal is to combine the SART and the EPIRB to create a device wherein the advantages of the SART and EPRIB are used. To help structuralize the project we devised a set of sub-questions to formulate an answerWhat is the difference between EPIRB and SART?What is an SART sailing?What is the frequency of SART?What is the frequency of EPIRB?What is the use of SART?When should I use an EPIRB? A Search and Rescue Transponder SART is an electronic device that automatically reacts to the emission of a radar. EPIRB is used to alert search and rescue services in the event of an emergency. What is the work of EPIRB? An Emergency Position Indicating Radio Beacon or EPIRB is used to alert search and rescue services in the event of an emergency. It does this by transmitting a coded message via the free to use, multinational Cospas Sarsat network. What is an SART sailing? A search and rescue transponder SART is a self-contained, waterproof transponder intended for emergency use at sea. These devices may be either a radar-SART, or a GPS-based AIS-SART automatic identification system SART. What does a SART do? What is Search and Rescue Transponder SART? SART or Search and Rescue Transponder is extremely vital equipment on the ship as it performs the job of a signal-man. It is a vital machine during distress for it helps in locating the position of the vessel in case it goes off-track. What is the frequency of SART? 9200 to 9500 MHz Specifications / Components FREQUENCY RANGE 9200 to 9500 MHz TEMPERATURE RANGE Operating -20degC to +55degC Ambient -30degC to +65degC ANTENNA BEAMWIDTH Vertical ± relative to the horizontal plane of the SART Azimuth Omnidirectional What is the range of EPIRB? Its signal allows a satellite local user terminal to accurately locate the EPIRB much more accurately — 2 to 5 km vice 25 km — than MHz devices, and identify the vessel the signal is encoded with the vessel’s identity anywhere in the world there is no range limitation. What is the frequency of EPIRB? The 406 MHz channel is 170 kHz wide with a center frequency at MHz. A 406 MHz EPIRB is part of the requirements for GMDSS. Older types of EPIRB’s use the 121,5 MHz or 243 MHz band. These were originally designed to be detected by overflying commercial or military aircrafts. What is EPIRB on ship? EPIRBs are tracking transmitters which aid in the detection and location of boats, aircraft, and people in Emergency Position Indicating Radio BeaconEPIRB is used to alert search and rescue services in case of an emergency. What is the use of SART? A Search and Rescue Transponder SART is an electronic device that automatically reacts to the emission of a radar. This enhances the visibilty on a radar screen. SART transponders are used to ease the search of a ship in distress or a liferaft. How do I activate SART? The SART is activated manually and hence response only when interrogated. When activated in distress situation SART response to a radar interrogation by transmitting a signal which generates 12 blips on the radar and turns into concentric circles as the range between the two reduces . When should I use an EPIRB? You should only use an EPIRB when there is grave and imminent danger. During an emergency, you should first try to communicate with others by using radios, phones and other signalling devices. Mobile phones can be used but should not be relied on as they can be out of range, have low batteries or become water-damaged.
Partof the City Sailing Sea Survival and Offshore Safety Course, we show you and explain both the EPIRB and the SART, this is part of the City Sailing RYA C
It seems to be a very simple question, but sometimes we may get misguided by contradicting statements in different sources. The problem is that unnecessary self-testing of this equipment can reduce the overall run time available in an emergency. Each self-test draws a small amount of energy from the battery. The answer is very simple. As per SOLAS requirements adequate information should be provided to enable GMDSS equipment to be properly operated and maintained. Thus the manufacturer’s instructions shall be used as a reference for such tests. Let’s compare several latest SART models of different makers and see what is stated in their manuals. 1. Maker Jotron; Model Tron SART20 “Tron SART20 requires the following maintenanceAt least every 6 transponder should be taken out of its bracket and tested against a radar, using the procedure … Note that the self-test use the internal battery and will reduce the operational lifetime of the equipment - therefore the test should be limited to not more than once every month“. 2. Maker Oriola; Model Kannad Marine Safelink “It is recommended to self-test the AIS SART annually; more frequent self-testing can put an unnecessary drain on the self-testing of the AIS SART can reduce the overall run time available in an emergency. Each self-test draws a small amount of energy from the battery.” Those statements in manufacturer’s instruction are making clear that this test is not performed for all SARTs based on some fixed interval like weekly, monthly, quarterly or yearly. On every vessel, it is necessary to refer to the manufacturer’s instruction to determine a test pattern for available SART. GMDSS Radio Log Book may have an Annex with test patterns of GMDSS Equipment. Just don’t be misguided by Message Markers like Daily, Weekly, and Monthly. Even SART in mentioned in the Monthly section but it is clearly stated that it shall be tested in line with the manufacturer’s instruction. Extract from MCA GMDSS Radio Log Book "3. Monthlya Each EPIRB shall be examined to check –i Its capability to operate properly by carrying out a self test function see manufacturers instructions without using the satellite system,..." Extract from AMSA GMDSS Radio Log Book Tests and checks of equipment and reserve power at intervals specified by the equipment manufacturer must be entered into the log. A summary of the operational capability of the equipment, together with the names of any station contacted during tests, should be recorded. If any of the radio equipment is found not to be operating satisfactorily, the Master must be notified and details of the deficiencies recorded in the The tests and checks of equipment may include daily, weekly or monthly tests. The operating manuals for the equipment should provide guidance on what tests and checks are recommended. Similar applies to the EPIRB as unnecessary testing will reduce the run time of the EPIRB in an emergency. Some manufacturers may limit self-test of EPIRB to not more than 12 times per year. It is good to remember what is stated in GMDSS Manual “406 MHz beacons are designed with a self-test capability for evaluating key performance characteristics. Initiating a beacon self-test function will not generate a distress alert in the COSPAS-SARSAT system. However, it will use some of the beacon’s limited battery power, and should only be used in accordance with the beacon manufacturer’s guidance.“ Conclusion In this article we just wish to remind that tests of EPIRB and SART should be performed on strict intervals as stated in manufacture’s manual and unnecessary testing shall not be allowed. Do you want to improve your GMDSS knowledge and results with exam test programs? Try our online GMDSS tests trainer - test program based on IMO Model Course "General Operator’s Certificate for the GMDSS". Every test question is referred to international regulations and standards and built in a similar way the exams for GMDSS GOC are built. Check the Full Version in catalogue or a Free Trial following this link. Grow with us! Register with Learnmarine today and become a part of a professional maritime society Register Wish you calm seas and best regards! For the latest news and updates you may also follow us on Facebook or Instagram. Learnmarine is a provider of custom-made online and in-class training as well as competency assessment for the maritime industry. Epirbtron 60. Sailor 5051 AIS-SART Product sheet. Tron Sart 20. Sailor Sart II. Sailor 4065 Epirb- Family. Featured recommendations. MF/HF-SSB Radiotelephones The MF/HF radio is an essential piece of GMDSS regulations providing long-range communication. TheSART - Search and Rescue TransponderIntroductionThe Search and Rescue Transponder SART is a self-contained, waterproof, floating radar transponder intended for emergency use at sea. They are designed to be used on board any vessel; ship, boat, or survival are 2 types of Search and Rescue Transponders, the “Radar SART” and the “AIS SART.” We will be discussing the Radar SART since it is the most common found on board smaller as well as non-commercial primary use of the SART is to allow rescue vessels or aircraft equipped with X-band radar common marine navigational radar, to home in on the exact position of the SART by enhancing the radar return so that it is clearly visible on the radar of any vessel including search and rescue and Rescue Transponders are typicallyCylindrical, measuring about 13”x3” cm;weigh in at less than 2 pounds kg;brightly colored in either high visibility yellow or international orange and;Lithium battery-powered with a shelf life of 5 years. Provide a minimum of 96 hours usage in standby mode, and more than 8 hours when actively RequirementsThe International Maritime Organization IMO, of which most nations are a signatory, requires all SOLAS vessels on international voyages to carry Search and Rescue Transponders as follows1 On vessels between 300 and 500 GRT.2 On vessels of over 500 GRT.1 For Roll On/Roll Off passenger vessels, per every four life states may have additional requirements for commercial and non-commercial vessels includingFishing Vessels;Passenger Vessels;Workboats;And in some cases ANY vessel that carries more than 1 life most recreational vessels are not required by law to carry a SART, the offshore fisherman, long distance cruiser, and bluewater passagemaker might want to give some thought to adding one to their safety equipment recreational vessels and life rafts provide very poor radar returns due to their construction small, fiberglass, wood, rubberized materials, etc. When you couple this with the possibility of sea return caused by heavy weather, ground clutter if near shore, or heavy precipitation, it may be near impossible to detect these targets at any useful range. Enter the “Search and Rescue Transponder.”The Radar SART, How it getting into a long drawn out explanation of how radar works, lets simply say marine navigation radar simply transmits very short radio waves from its antenna and using the time required for a reflection to return and the direction of the radar antenna at that moment, it can determine the range and bearing of the object that caused the reflection and display that information on the radar Search and Rescue Transponder operates much like the familiar Radar Beacon RACON found on many aids to navigation. When swept by a pulse from a vessel’s radar, the RACON will transmit a series of dots and dashes Morse code and these will be displayed on the vessels radar screen. This enables the navigator to easily identify a particular ATON. See illustration right. This RACON is showing 3 dashes which is Morse code for the letter "O."The SART on the other hand, paints 12 unmistakable bright dots on the radar screen when a vessel gets within range. The closest dot to your vessel indicates the actual SART’s Search and Rescue Transponder incorporates both a radio receiver and a transmitter tuned to the frequency of marine navigation radar. When the SART is interrogated swept by a radar beam the SART receiver picks up that signal and responds by generating and transmitting 12 amplified signals with only micro seconds delay between each. This results in the characteristic 12 dots displayed on the radar screen see illustration left. It does this any and every time when swept by a a Search and Rescue Transponder is turned on, it goes into what is known as the “Standby Mode.” This means that the SART is operational and waiting to be interrogated by a radar. When it detects a radar pulse, it automatically switches into the “Active Mode” where it generates an amplified signal and transmits 12 pulses back to the interrogating radar. At distances greater than 1 NM, the radar screen will display the SART transmissions in the familiar 12 dot no radar pulse is detected for a period of approximately 15 seconds, the SART automatically returns to the standby mode to await further SART models are also equipped with a light and buzzer that will activate when interrogated alerting you that it has picked up a radar pulse and is the distance to the SART closes to within approximately 1 NM, the 12 dot display will start to become concentric arcs centered on the SART. The length of these arcs will gradually increase as the distance finally . . .These arcs will gradually become full concentric circles surrounding the location of the SART, indicating that you have arrived at the SART's Range of a SARTBecause of the frequency used by the SART, to GHz known as SHF or Super High Frequency, the Search and Rescue Transponder is considered to be a line of sight device much like the VHF radio. The antennas must be able to “see” each other to operate effectively. This means that the higher you are able to mount the SART when in use, correspondingly increases the effective SART mounted 1 meter or above the surface has a radio horizon of only slightly more than NM. Luckily most vessels radars are typically mounted at or above 10’ from the surface. This means that the effective detection range will increase to slightly less than 6 NM. When you factor in larger vessels and ships with radars mounted at 75’ or greater above the surface, initial detection may be out as much as 12 NM’s. Search aircraft flying at altitude, may likely detect the SART signal out to a range of 30+ NM’s. The moral of this story; the higher that you can mount the SART above the surface the greater range that it will be detected the Purchase of a SARTAn EPIRB or a Search and Rescue Transponder? Remember, a SART is not an alternative to an EPIRB, they are designed to fulfill two completely different functions. All things being equal, the ideal situation of course is to have you are just beginning the fitting out of your boat, the question may arise whether the purchase of an EPIRB or a SART is in your best interest. In this case, the purchase of a 406 MHz EPIRB will provide you with far more capability in the event of an emergency. Providing SAR teams not only with position accuracy often times within a few meters, but with additional information such as the vessel name, vessel characteristics, the vessel owner, and emergency contact both the EPIRB and SART being in the same general price range, the decision to add a Search and Rescue Transponder to your onboard safety equipment is often a matter of budgetary constraints. Remember that the SART provides capabilities that the EPIRB doesn’t. Specifically the capability of being easily located, even in the poorest of visibility, by any vessel equipped with standard marine radar that is within range..