Which VHF channel to use for on-boat operations?

[Trawler2016]

Maybe it is just me, but I would prefer to NOT use the VHF radio for talking between skipper and crew for tasks like docking.
Those channels can get pretty crowded in some areas.
I think the headphone mic sets are far more practical and keep the radio traffic down and both hands free. Sena or Eartec both work well.
My two cents worth.
Bill

[Dockhead]

Originally Posted by paulears

If you are using the radios for docking, then it becomes a safety matter and as people have said, low power operation on 15 or 17 is a sensible place to have the conversation. It's not ideal chit-chat. Historically the 1W power limit was helpful during the transition years back from the old wider bandwidth radios (The Sailors, in particular) when 25W either side of 16 tended to leak a bit, and limiting power made sense, and probably still does. Remember that so many of our 'rules' do NOT appear in your licence if you read it in EU and UK. Lots are more codes of practice and agreed band planning. OFCOM in the UK seem quite happy with the self-policing. The Coastguard will jump on anyone doing chat or even too long overs on 16, which seems appropriate, but while 'port operations' is a pretty good indicator of the channel activity, what exactly port operations is is not written down that I have found. Somebody on 15/17 would not be a problem. In my own area, there are plenty of unoccupied channels, and many are used almost as private channels.

The suggestions to use PMR446 are valid, but that means two different types of radio and I personally believe that safety is an important feature of any radio, so NOT being able to call for help on a radio is a negative.

Alternatively, the lack of channel specific terms in the licence would also mean that if you were to buy radios that have all the available channels fitted - including the historically now unused ones, there are plenty of marine channels available that do not exist on most. The old ship to shore telephone patch channels are totally unused in some areas, and the shore stations long closed down. These duplex channels are now unused in my area and one local boat firm uses one of them simplex, on modified radios. This does not appear to contradict the current licence. They're still live in some places abroad. The other alternative is to buy programmed radios - these are radios that have the usual common marine channels but can also operate on the short term hire channels or business lite channels - which are in the middle of the marine allocation. So you put in all the common marine channels and then a private channel. This won't be in any conventional marine radio. Again, there is no licence issue with having two licences and one radio.

However - just do it on 15/17 on low power.

I think this is really well argued. Made me think.

I've never felt the need for radio comms while docking or anchoring, so bit of an academic question for me, but on reflection you are so right about not wanting different types of radio on board. And not just calling for help, but any other kind of comms. "Damn it, I've got the wrong radio. " Surely you want every radio on board to work with every other radio, to maximum possible extent.

In our summer in the Arctic, with no mobile phones, we used marine vhf for all kinds of comms, as the locals do. Normally i think everyone uses mobile phones for everyday comms, but there are cruising destinations where they don't work.

[paulears]

I sell radios and other marine electronics and while many customers are knowledgeable and have an element of technical ability, the vast majority are hopeless and I suspect very few have taken the Short Range VHF Exam they should have in the UK. I constantly get questions about range - as in how far will XXX go? I try to explain that it's antenna height not power, but obviously a 25W radio goes further, and it's hard. I've sold a radio to a guy recently and he said it was useless and wanted a refund - which I happily did. When processing the refund I noted his post code and googled it. He lives 120 miles from the nearest coastline and is in a valley between mountains!

I'd guess that people buy radios for safety - as in they pull it out and call for help. Probably with flat batteries and the antenna unscrewed and lost - but safety IS their reason for radios. On vessels large or small, the understanding that a radio is not just a radio is quite worrying. My office is in a harbour, and I run an analyser when I'm there so I can see where the traffic is - and it's surprising where you find people. Many have their own out of the way channels. Over the summer, we get some ducting, and as a result, in the middle of a race using channel 37 (37A, simplex) you discover two foreign people in Holland having a chat. Channel 37 is pretty much UK only, so they probably found it very quiet over there and use it as a chat channel - the race officials had great trouble as they were loud and very clear here.

I think radios, proper marine channel ones, are more important now - as people are docking off the boat, using remote control thrusters. I see this as even more important that they have a radio. A stuck button that takes the boat away from the pontoon, possibly with the person in charge not on it means safety is important. As I said, locally we have all sorts of channels in use but they co-exist happily as long as they avoid our port ops on 12, lock ops on 73 and of course 16. The people who use 6 and 8 are from different companies but rarely get in the way of each other, and 15 and 17 here are not occupied very much at all. What I have noticed is that the better users are in radio terminology, the more they are left alone. Two people using radios properly - with precise comms for short 'overs' are not annoying. The plonkers who still say 'over and out' and make you giggle/sigh might well get talked over by some of the professional mariners, perhaps in desperation. Marine comms is by and large a self-policed system once off the important channels. We have North Sea platform lifeboat training and they use an out of the way channel and frequently get everything wrong and it's quite entertaining - but a totally legitimate use of the radio, even though strictly speaking the radio users will NOT have individual licences, just the one for the lifeboat.

I appreciate that when you go down to say, the Solent - it's damn busy and so many ports and marinas channel space is at a premium, but bow or stern end handhelds have little more than a few miles range at that height, so co-channel interference is manageable.

It's interesting to look at the comms use of cruise ships. Engineering are rarely to be found with marine radios - using their short range systems on UHF and VHF, but bridge operations always use marine radios, with the safety provision high on the list. Those with no link to safety, navigation or external communications are off marine band. Leaving it free for marine stuff. That seems to work.

[Auspicious]

Originally Posted by paulears

My office is in a harbour, and I run an analyser when I'm there so I can see where the traffic is - and it's surprising where you find people.

What do you use? A full-up communication analyzer, a scanner, or an SDR with a waterfall? A real analyzer is a pretty expensive piece of kit.

Originally Posted by paulears

It's interesting to look at the comms use of cruise ships. Engineering are rarely to be found with marine radios - using their short range systems on UHF and VHF, but bridge operations always use marine radios, with the safety provision high on the list. Those with no link to safety, navigation or external communications are off marine band. Leaving it free for marine stuff. That seems to work.

In my experience all the inside communications are usually half-duplex UHF that run through a "leaky coax" repeater system. These same sorts of systems are used in some office buildings for management and tenant services. The repeater is pretty conventional but instead of the circulator/isolator connect to an antenna it goes to a big run of purposely poorly shielded coax with a termination resistance. This does a great job of signal distribution. Anything related to onboard operation is here: bridge, engineering, hospitality, housekeeping. The little radios everyone carries are here. To my knowledge marine VHF is fixed radios on the bridge, in the chart room, captain's sea cabin, and maybe a few ancillary places. I'm sure there are some handhelds kicking around. Lifeboats of course.

Related to comms, the Inmarsat C installations I'm familiar with are interesting. The direct dial phone rings on the bridge. After some number of unanswered rings the extension in the captain's cabin starts ringing. You can imagine the captain finds this very irritating and the watchstander gets a talking to.

[paulears]

Rigol with tracking generator mainly for aligning cavities but very handy for spotting the folk still using 50KHz kit and tracking noise sources. Leaky feeder instals are on some of the military vessels we get in port here and on the fisheries ships but the thing I noticed on P&O was the number of discrete channels they used outside of marine band. I often wondered how they coped once out of international waters where so many of their channels would not be legal at all!

[Auspicious]

Ah. I had a bunch of big Anritsu devices in one of my corporate jobs, but now I just rent stuff when I need it.

[paulears]

I put the analyser on for an hour or two and found pretty much what I expected, but also a few interesting things. It's clear people are using the two channels either side of 16 - not 15 and 17 as we talked about, but the upper channels 75 and 76. I'd never have thought about listening there. They have the same 1W rule here in the UK, but I wasn't aware of any activity there. The usual suspects are clearly in use in Lowestoft Harbour area - so channels 6,8,69, 11,71,73,14,75,16,76 - DSC on 70 has a little blip but there is somebody using nearly channel 78 - it's actually 156.9125MHz - so off-frequency for marine channels? No idea what that actually is?

It's interesting to have a snapshot of where people are talking. From my office up the river, the vessel on channel 8 would be at sea. The channel 6 users are handheld users on the river - so maybe a mile away as are most of the other users. The way the analyser is set up is that signals you'd find noise free are around the -65dB level. -78dB is easily readable but noisy, and lower than this noisy but usually readable. Channel 0 on the left has the coastguard and lifeboat traffic - but any of the old ship to shore channels below ch 6 (156.3MHZ) appear totally empty. In the UK, I can't find anything specific in our licence that says you cannot use them? Cleary in other parts of the world they may still be in use for telephone patches. Our normal radios only have these as duplex channels, but a few radios have channel 2 available as 2A as well - and this would be virtually unnoticed even in busy areas with heavy radio traffic.

[Auspicious]

I'm surprised channel 13 doesn't show up at all.

[s/v Jedi]

Channels 75 and 76 are SOTDMA AIS transceivers transmitting to AIS satellites.

[Auspicious]

Originally Posted by s/v Jedi

Channels 75 and 76 are SOTDMA AIS transceivers transmitting to AIS satellites.

Footnotes please? ITU-R M.2092-0 is still under discussion to my knowledge. AIS is on what were 87B and 88B and current satellite AIS receivers are on those channels.

[s/v Jedi]

Originally Posted by Auspicious

Footnotes please? ITU-R M.2092-0 is still under discussion to my knowledge. AIS is on what were 87B and 88B and current satellite AIS receivers are on those channels.

No, all SOTDMA transceivers, which is all class-A and the newish class-B+ transmit on channels 75 and 76. This is tx only, as it is just the ais satellites that listen, not shipstation transceivers.

You can find this info in the official channel list, under footnotes n and s: https://www.navcen.uscg.gov/?pageName=apps18

[paulears]

In the UK - 156.775 and 156.825 are listed currently as comms channels. We don't have AIS there. They're allocated to port operations and ship movement. Interesting how different it can be.

[s/v Jedi]

Originally Posted by paulears

In the UK - 156.775 and 156.825 are listed currently as comms channels. We don't have AIS there. They're allocated to port operations and ship movement. Interesting how different it can be.

No, AIS is worldwide, so is satellite AIS. Other, limited use at reduced 1W power is allowed. See the channel list I posted.

[paulears]

Well, I will tell OFCOM what they print in my licence is wrong then? They have this - updated in 2020 and channel 73 is scheduled for AIS - but this is the current International allocation, ratified by the UK. We also have 161.425MHz our channel M2 and M1/37A 157.850MHz currently in use and NOT requiring the user to have the VHF short range examination pass, or oddly, a marine licence - they're in use by marinas and yacht clubs.

Here is a like to the Government document https://www.ofcom.org.uk/__data/asse...-licensing.pdf

[s/v Jedi]

Originally Posted by paulears

Well, I will tell OFCOM what they print in my licence is wrong then? They have this - updated in 2020 and channel 73 is scheduled for AIS - but this is the current International allocation, ratified by the UK. We also have 161.425MHz our channel M2 and M1/37A 157.850MHz currently in use and NOT requiring the user to have the VHF short range examination pass, or oddly, a marine licence - they're in use by marinas and yacht clubs.

Here is a like to the Government document https://www.ofcom.org.uk/__data/asse...-licensing.pdf

Time to update their docs if they lack this info. Again, every class-A and every sotdma class-B AIS transceiver, and we’re talking hundreds of thousands around the UK, send AIS message 27 on channels 75 and 76.