AIS in the Solent

prv said:
I think Bob's point was the same as mine - if it's a bright sunny day, why on earth are you peering at a little screen to locate the large ships which are perfectly visible to the naked eye?

Pete
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Well, cos some of them are not. eg if a ship is leaving its berth on the Itchen it may influence ones choice of route past the Brambles to minimise possible confrontation. or if a ferry is leaving its berth in Portsmouth the it is well to be aware of that when crossing the channel from Portsmouth to the outer Solent.

As I have said a couple of times I'm perfectly capable of using my eyes but the presence of so many AIS vessels renders the whole thing pointless in these confined waters.

To be honest I only the found the AIS of use twice over the entire Friday/Saturday when singlehanding from Plymouth to Brighton, onbce was off the dorset coast at night when it was difficult to judge the distance of a sailing vessel with a tricolour on a collision course by eye and the other was by day in Lyme Bay when a MFV was behaving erratically (as they all do).

However I applaud your defence of the right of the legions of leisure boats to broadcast as and when they like without regard to the overall effectiveness of the tool.
 
jimi said:
Well, cos some of them are not. eg if a ship is leaving its berth on the Itchen it may influence ones choice of route past the Brambles to minimise possible confrontation. or if a ferry is leaving its berth in Portsmouth the it is well to be aware of that when crossing the channel from Portsmouth to the outer Solent.
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I find it easier to monitor VTS (Ch12) and QHM (Ch11) were that sort of information is given during the vessel's request to depart her berth and during the passage.
 
Giblets said:
I find it easier to monitor VTS (Ch12) and QHM (Ch11) were that sort of information is given during the vessel's request to depart her berth and during the passage.
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I'm sure you do! cos with AIS its friggin impossible .. which was the whole point of the OP
 
jimi said:
Well, cos some of them are not. eg if a ship is leaving its berth on the Itchen it may influence ones choice of route past the Brambles to minimise possible confrontation. or if a ferry is leaving its berth in Portsmouth the it is well to be aware of that when crossing the channel from Portsmouth to the outer Solent.
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Doesn't take very long between a ship leaving its berth up southampton water and you being able to see it. The VTS broadcasts which DJE and Giblets mentioned will tell you all upcoming movements (including vessels which are *about* to leave): rather more useful if large vessel movements affect your strategy. I'll argue that in/out of Portsmouth the channel is narrow enough and you've got enough visibility each way that visually identifying when you can cross is not an issue. besides, there's so much commercial traffic do you really want to be mucking about pointing and clicking to work out what's the Normandie and what's the St. Clare*? I'd rather be paying attention to what is visible.

Being berthed in Portsmouth harbour (or I imagine, anywhere similar) commercial traffic alone makes it necessary to turn all your AIS alarms off anyway. In the nearly 3 years I've had it I've never felt any need for AIS in the solent. Mine hasn't been turned on since just north of the traffic coming back from Alderney a couple of weeks ago.

EDIT * For non-locals, the latter ferry will turn right towards the isle of wight coming out of Portsmouth and not affect your plans to cross the main portsmouth channel. The former is much bigger and going to france via the channel you're wanting to cross to get to chichester and the mysterious and exotic east, although if you can't see it I argue you have plenty of time to cross
 
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The Solent is fairly unique in the Uk, in that there are far too many people with far too much money to spend on toys (such as AIS, Bow thrusters, etc.), but at the same time an awful lot of them also have little or no boat handling skills or sea miles, and no real understanding of how and when to use such toys.

Your eyes and ears are the most useful things to use in the Solent.
 
laika said:
In the nearly 3 years I've had it I've never felt any need for AIS in the solent. Mine hasn't been turned on since just north of the traffic coming back from Alderney a couple of weeks ago.
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+1

If I'm staying local ( ~ Chichester to Poole) I don't even bother taking the cover off. Despite the fact that with my Watchmate I probably could filter out a fair proportion of the leisure traffic. It's just not relevant to that type of sailing.

Pete
 
jimi said:
Well, cos some of them are not. eg if a ship is leaving its berth on the Itchen it may influence ones choice of route past the Brambles to minimise possible confrontation. or if a ferry is leaving its berth in Portsmouth the it is well to be aware of that when crossing the channel from Portsmouth to the outer Solent.

As I have said a couple of times I'm perfectly capable of using my eyes but the presence of so many AIS vessels renders the whole thing pointless in these confined waters.

To be honest I only the found the AIS of use twice over the entire Friday/Saturday when singlehanding from Plymouth to Brighton, onbce was off the dorset coast at night when it was difficult to judge the distance of a sailing vessel with a tricolour on a collision course by eye and the other was by day in Lyme Bay when a MFV was behaving erratically (as they all do).

However I applaud your defence of the right of the legions of leisure boats to broadcast as and when they like without regard to the overall effectiveness of the tool.
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Jimi its the very latest, in boat games consoles, a must have, See wot i got, Im a very clever rich dickie
 
laika said:
Doesn't take very long between a ship leaving its berth up southampton water and you being able to see it. The VTS broadcasts which DJE and Giblets mentioned will tell you all upcoming movements (including vessels which are *about* to leave): rather more useful if large vessel movements affect your strategy. I'll argue that in/out of Portsmouth the channel is narrow enough and you've got enough visibility each way that visually identifying when you can cross is not an issue. besides, there's so much commercial traffic do you really want to be mucking about pointing and clicking to work out what's the Normandie and what's the St. Clare? I'd rather be paying attention to what is visible.

Being berthed in Portsmouth harbour (or I imagine, anywhere similar) commercial traffic alone makes it necessary to turn all your AIS alarms off anyway. In the nearly 3 years I've had it I've never felt any need for AIS in the solent. Mine hasn't been turned on since just north of the traffic coming back from Alderney a couple of weeks ago.
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Sorry - with Jimi all the way here.

It's one reason why I never bothered updating the chartplotter as it's current firmware ignores AIS class B signals.

The reason we used to use it in the Solent was to identify ships that would be coming through so we could go be more relaxed about where we sailed. The shortest course was preferable, but not if we had to then deviate to get out of a tankers way, so in that situation we'd take a longer course around. Don't bother with alarms in the Solent.

Btw - visibility isn't always good - plenty of times we left Beaulieu in sunshine to find that we couldn't see Cowes let alone Portsmouth - still don't need AIS class B in that situation because you can see enough to avoid similar sized/speed boats, it's the big boys that you want to ensure you stay well clear of.
 
fireball said:
The shortest course was preferable, but not if we had to then deviate to get out of a tankers way
[...]
Btw - visibility isn't always good - plenty of times we left Beaulieu in sunshine to find that we couldn't see Cowes let alone Portsmouth
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As a regular racer the absolute optimum path will be more important to you than to me and your experience of estimating the arrival time at Prince Consort of various types of vessel which are not yet visible (and whose speed will probably change from when they've just slipped) will undoubtedly vastly exceed mine.

Last time I was out in really poor vis in the solent I confess that I did have the AIS on. My original contention was really about normal conditions. It's probably not entirely useless to know if there's a bunch of sunsail firsts heading towards you when vis is really low...
 
jimi said:
On passage with tidal gates, the optimum path is not entirely irrelevant!
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I think we're talking a few minutes. Critical if you're racing round the cans, irrelevant for the average cruiser traversing the solent compared with time spent avoiding racing fleets. To ever sail an optimum course through the solent during the daytime you've got to be heading upwind on starboard and have nerves of steel...
 
laika said:
I think we're talking a few minutes. Critical if you're racing round the cans, irrelevant for the average cruiser traversing the solent compared with time spent avoiding racing fleets. To ever sail an optimum course through the solent during the daytime you've got to be heading upwind on starboard and have nerves of steel...
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Depends if you're trying to miss the ebb tide out of Chichester ... we don't all sail within lake solent ... some of us venture outside (well used to anyway)
 
fireball said:
Depends if you're trying to miss the ebb tide out of Chichester ... we don't all sail within lake solent ... some of us venture outside (well used to anyway)
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.. or even trying to catch the last of the tide through the Owers .. which I just managed ;-)
 
I'm with Pete on this one. The issue has nothing to do with who is transmitting and everything to do with how you consume that information via (presumably) the plotter. Write to your plotter manufacturer if it bothers you, but transmitting AIS is a safety feature and personally I don't think it should be disabled. A good example of this is a yacht which was overdue yesterday which Portland coastguard was looking for. Had they been transmitting AIS the coastguard could easily have reviewed logs and found a last known position. As it was they transmitted Pan Pans all day asking for info and eventually found the boat in a harbour with crew safely ashore.
I've no desire to take the battery out of my PLB when I'm on an easy sail in the Solent, nor do I remove it from my LJ. My LJ is automatic and has an automatic light in it. The VHF is wired to bypass the switch panel and permanently gets position from the GPS. All of these things are there for safety, and should be configured in such a way that I don't have to remember to enable them for them to help me. You may argue that it becomes routine but I suspect most people would turn it on as an exception rather than rule and therefore may forget on the yearly channel hop.

It would be trivial for the plotter people to filter on screen stuff to >100T for instance, all the info is there and it needn't disable the alarms for this either.
 
lustyd said:
I'm with Pete on this one. The issue has nothing to do with who is transmitting and everything to do with how you consume that information via (presumably) the plotter. Write to your plotter manufacturer if it bothers you, but transmitting AIS is a safety feature and personally I don't think it should be disabled. A good example of this is a yacht which was overdue yesterday which Portland coastguard was looking for. Had they been transmitting AIS the coastguard could easily have reviewed logs and found a last known position. As it was they transmitted Pan Pans all day asking for info and eventually found the boat in a harbour with crew safely ashore.
I've no desire to take the battery out of my PLB when I'm on an easy sail in the Solent, nor do I remove it from my LJ. My LJ is automatic and has an automatic light in it. The VHF is wired to bypass the switch panel and permanently gets position from the GPS. All of these things are there for safety, and should be configured in such a way that I don't have to remember to enable them for them to help me. You may argue that it becomes routine but I suspect most people would turn it on as an exception rather than rule and therefore may forget on the yearly channel hop.
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I guess we arrive at the same point by slightly different routes :)

Your safety argument, though not incorrect, is not a priority for me. I just think that the oft-suggested idea of turning off the transmitters is back-arsewards from an engineering point of view, and implausible from a pragmatic one. Better handling on the (currently extremely primitive) receivers is so obviously the correct answer that it annoys me when people can't see past the dumb one.

Pete
 
prv said:
I guess we arrive at the same point by slightly different routes :)

Your safety argument, though not incorrect, is not a priority for me. I just think that the oft-suggested idea of turning off the transmitters is back-arsewards from an engineering point of view, and implausible from a pragmatic one. Better handling on the (currently extremely primitive) receivers is so obviously the correct answer that it annoys me when people can't see past the dumb one.

Pete
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I did come to that conclusion the same way, the safety gear thing was kind of a different point but one I thought worth mentioning :)
 
Just ask yourself this...

How many collisions with big ships were there in the Solent before there was such a thing as AIS? My guess would be no more than there are now.

AIS has it's place, and the Solent is not it.
 
Bobc said:
Just ask yourself this...

How many collisions with big ships were there in the Solent before there was such a thing as AIS? My guess would be no more than there are now.

AIS has it's place, and the Solent is not it.
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But as both Jimi and I have said - it's not about collision avoidance - it's about convenience - being able to select an appropriate course that anticipates ship movements that you can't see yet.

Filtering the display & alarms could resolve the "issue" as well - this is essentially what we used to do with our older firmware.
 
prv said:
I guess we arrive at the same point by slightly different routes :)

....... I just think that the oft-suggested idea of turning off the transmitters is back-arsewards from an engineering point of view, ...
Pete
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There is a finite limit to the number of timeslots, so there will come a point where the number of transmitters needs to be limited.
Or more channels will be needed, like with mobile phones.

TBH, the course of many ships in the Solent is hard to predict in detail more than a very few minutes ahead.
The big 'uns out of Fawley are easy, but the medium sized stuff needs thought sometimes.

But sailing in the Solent always requires knowing where you are relative to the channels and knowing what the tide is doing.

I can only think of one time when AIS would have been significantly useful, and that was thick fog.
Rest of the time it is a toy, or at worst a waste of time that would better be spent looking around.

Cross channel is different, for that I really like AIS.
 
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