AIS SART vs AIS MOB

[bedouin]

I am just about to buy an AIS beacon. Reasoning is as follows. I often sail single handed in areas of poor VHF reception. I'm not intending to replace out of date flares. I have 2 epirbs but If I need assistance I want the nearest vessels to be aware. The idea that I can press an AIS button along with the DSC distress then get on with sorting the emergency is appealing. When single handing I would dread having to call on channel 16 and spend ages answering a long list of questions, what colour is your vessel etc when I could be working on preventing my vessel sinking.

I am not sure what AIS adds to DSC in that circumstance. They use the same basic technology so signal propagation is the same but pretty much every vessel out there now has a VHF DSC and will pick up the DSC distress. Many don't have the ability to respond in the same way to AIS.

Without having the ability to confirm with a voice call I am not sure what sort of response you will see to a random AIS alert

IMHO (others differ) AIS is good for crew where the people on your own boat and going to be doing the recovery. For single handed I would always go for EPIRB then DSC

 

[Vronsky]

I am just about to buy an AIS beacon. Reasoning is as follows. I often sail single handed in areas of poor VHF reception. I'm not intending to replace out of date flares. I have 2 epirbs but If I need assistance I want the nearest vessels to be aware. The idea that I can press an AIS button along with the DSC distress then get on with sorting the emergency is appealing. When single handing I would dread having to call on channel 16 and spend ages answering a long list of questions, what colour is your vessel etc when I could be working on preventing my vessel sinking.

Some VHF's have GPS position included in the DSC distress message, but where I boat inland, there's no DSC. Spelling a GPS position etc. via VHF (or GSM) will be a challenge in emergency situations. The beacon sends out the MOB text + GPS position via AIS (+DSC by the way) , then +also do a PAN PAN call via VHF to boats near to explain

 

[bedouin]

Some VHF's have GPS position included in the DSC distress message, but where I boat inland, there's no DSC. Spelling a GPS position etc. via VHF (or GSM) will be a challenge in emergency situations. The beacon sends out the MOB text + GPS position via AIS (+DSC by the way) , then +also do a PAN PAN call via VHF to boats near to explain

Total thread drift of course but if I were in distress on inland waters I would not be thinking of using GPS coordinates to give my location. Good old fashioned "half mile south of xxx" is going to be much more effective, Another bit of drift to me MOB is (almost) always Mayday, not PAN PAN.

 

[Buck Turgidson]

Total thread drift of course but if I were in distress on inland waters I would not be thinking of using GPS coordinates to give my location. Good old fashioned "half mile south of xxx" is going to be much more effective, Another bit of drift to me MOB is (almost) always Mayday, not PAN PAN.

and orange smoke will get the attention of nearby vessels.

 

[Tranona]

Some VHF's have GPS position included in the DSC distress message, but where I boat inland, there's no DSC. Spelling a GPS position etc. via VHF (or GSM) will be a challenge in emergency situations. The beacon sends out the MOB text + GPS position via AIS (+DSC by the way) , then +also do a PAN PAN call via VHF to boats near to explain

That does not sound right. The DSC transmission of position is a function of the radio, not where it is located. That is the whole point of the system. As to how you describe where you are, the most common is the Lat and Long when you are at sea, or in the UK common to use the OS grid reference if land based. some rescue services prefer to use bearings to and from a known point.

To be clear though, the number of times a DSC red button call is the prime method of communication is tiny and as I said earlier almost all communications are voice calls Following the standard VHF procedures which you are required to learn and be tested on before you get your certificate to operate a VHF. A DSC emergency only signals a potential problem at the location. It needs to be followed up with voice communication to be effective.

I cannot believe that in the Netherlands there is no a well honed system for dealing with emergencies using voice communication via VHF

 

[Bilgediver]

Some VHF's have GPS position included in the DSC distress message, but where I boat inland, there's no DSC. Spelling a GPS position etc. via VHF (or GSM) will be a challenge in emergency situations. The beacon sends out the MOB text + GPS position via AIS (+DSC by the way) , then +also do a PAN PAN call via VHF to boats near to explain

You seem to have certain misunderstandings regarding DSC Messages. The GMDSS radio WILL NOT send a message unless it has a position input to the message.. This can be input manually or obtained from the vessels GPS and is always included in the message regardless of whether the vessel is on inland, coastal passage. The rescue services would locate you by using the GPS on their boat or helicopter. We also use The Three Little Word system in the UK.

DSC Handheld radios may not be legal in your country as for many years could only be licensed in the UK. Check this!

I would not rely on AIS when in inland waters as you will be severely limited by the number of vessels in your area who have the equipment fitted to respond t such an emergency message . Thus might not be the case on coastal passages.