Sailing yacht radar visibility

[Robin]

How could RN and Border Force see much further than 20 nm, if as you say radar mounted on top of a 100m cliff is 21 miles? I've yet to see a naval vessel with a mast for a radar 100m in the air!

Anecdotal again then. We were southbound out of Poole bound for channel Islands late season and in a thick fog bank. We had a target showing on our radar going westbound but looking too close for comfort In theory we were stand on vessel but decided to take some 'action' to improve the CPA so stayed on same heading but slowed to almost a standstill, expecting to see the target track now pass well clear ahea, but it did not. we had stopped, target stopped, we moved off again so did target, repeated several times. Then another and much larger target appeared headed north and probably a ferry. 'Cat and mouse 'target stopped playing with us and took off rapidly well out of our way, phew! We later heard one of the customs cutters (Searcher or Seeker?) were out there that night and may well have been using us as a training aid. All this was pre AIS days and we had only our own Furuno CRT radar and the same Firdell Blipper mentioned earlier. Sea state was calm and we were under engine and autopilot.

 

[grumpy_o_g]

In less than a day?

Anyway there's all kinds of things flying around. Some say less than 1km, some say 8-10 nm, some say 20 nm....

So all I can reasonably take away is a sailing vessel probably at most can be seen on radar from 20nm away

Sadly the correct answer is all and none of them....

That nice Mr Morris hit the nail on the head when he said that it's whether or not you can see them that matters, both legally and in reality. You should never rely on someone else having seen you if you can possibly avoid it.

 

[john_morris_uk]

In less than a day?

Anyway there's all kinds of things flying around. Some say less than 1km, some say 8-10 nm, some say 20 nm....

So all I can reasonably take away is a sailing vessel probably at most can be seen on radar from 20nm away

Nice to hear from you again. What do you think is achieved by being ‘seen’ on radar at 20 miles?

 

[grumpy_o_g]

I don't have a copy to hand, but I think there conclusion was that none of them were very good at some angles. However, since yachts move around all the time, the chances of one of those dud angles being consistently presented is quite low. This is an area in which there really is no substitute for proper field testing. I have had an EchoMax on my list for a while, but it's not imminent, thanks to AIS.

Unfortunately all the field testing I've ever done or heard about suggests that passive reflectors are little better than nothing most of the time. I know from my time up in Lossiemouth just how hard it is for Nimrods and Sea King SAR choppers and other military kit to find a small boat in the middle of nowhere. The military kit from back then was probably just about as good as the newer marine stuff to the civilian market but even the modern military stuff struggles sometimes - and small boat detection has become a but of speciality these, mainly thanks to drug smuggling. Throw in a less than interested watch-keeper and a fairly basic and aged radar set-up and I'm definitely working on the basis I haven't been seen even if they're actually talking to me.

 

[Robin]

Nice to hear from you again. What do you think is achieved by being ‘seen’ on radar at 20 miles?

Good question but there are some who will alter course for an AIS 'target' seen at long range which may well change considerably as the range closes. Sometimes too much information hinders rather than resolves. As a leisure sailor over many years in the busy Channel waters many with no VHF,only a Seafix RDF and spinning red neon depth sounder for electronics we never had a collision and fewcheek clencher misses. We did always have either a catch rain mounted octahedral or a blipper. There were times in fog when we heard foghorns that appeared to be avoiding our space. A clubmate who in his work life was a First Officer on bulk carriers once told us the most dangerous time was a clear day with perfect vis because in fog or bad conditions the best operators and the master were on bridge duty rather than the trainees or spares.

 

[Jamie Dundee]

I know from my time up in Lossiemouth just how hard it is for Nimrods and Sea King SAR choppers and other military kit to find a small boat in the middle of nowhere.

To be fair though that is radar detection from the air. I’ve been struck by how much more efficient my radar is when the boat is on the water rather than above the water on the hard. Much more separation of sea and target at sea level than from higher up.

 

[alan_d]

A century isn't a big deal in geology.

I think the point being made is not that the topography has changed in a century but that our accuracy in fixing our position on the Earth's surface has. It is no good knowing your position to the nearest 10 metres if the chart you are plotting it on is half a mile out.

 

[The Professional]

Nice to hear from you again. What do you think is achieved by being ‘seen’ on radar at 20 miles?

Nothing. My original question was is it true such a sailing vessel could only be seen on radar from 3 nm away, or is that scare mongering by someone trying to sell me radar reflectors?

My comment about 20 nm was the closest thing we have achieved to an approximation in this thread is more than nothing, but probably less than 20 nm... which as you infer isn't really of much help.

 

[Neeves]

I'm not entirely sure what you mean in your post No 88 - b ut I'd say that being identified at 20nm is the extreme, at best, and more likely at much closer range

I would hope that in most cases if someone was 3 miles away from you, they would see you - excepting in fog/mist - but I would not rely on them seeing you, but you should see them - and if necessary do something about it.

In the context in which you posted - the salesman was scaremongering (which I think someone said early on in the piece) - and whilst the salesman's product might be good - I'd buy from someone else (but I like people to be honest and accurate - not scare monger (we have plenty of scaremongering in anchor threads without it happening on radar threads and being used by salesman).

What really interests me is what you are going to do now. You started the thread to clarify in your mind the veracity of a claim regarding the need to have a radar reflector and I assume you did not go to buy a shackle and this was part of the conversation. So you must have instigated the discussion - so what are you going to do? I only ask as minimising risk is simply - prudent - and I'm interested in how people prioritise and then resolve - risk.

Jonathan

 

[Pye_End]

Nothing. My original question was is it true such a sailing vessel could only be seen on radar from 3 nm away, or is that scare mongering by someone trying to sell me radar reflectors?

My comment about 20 nm was the closest thing we have achieved to an approximation in this thread is more than nothing, but probably less than 20 nm... which as you infer isn't really of much help.

What is the benefit of 20 miles over say 10 miles?

The benefit of a radar reflector is not so much being seen at very long distances v's closer distances, but being seen at all.

Take your friend's advice - buy and fit a decent radar reflector - there are no down sides.

 

[PaulRainbow]

Given that you are required by Solas V to fit one and that it might make you more visible, why would anyone not fit one ?

 

[TernVI]

.....

In some other context I recall being told that the echo from a plastic or wooden yacht is from its interface with the sea, that is the radar is getting its echo from the hole the boat makes in the water. Probably works better beam on...

The sea doesn't have to be terribly rough to have yacht-sized gaps between waves.

 

[rogerthebodger]

Solas V apply to pleasure vessels under 150 GT.

Is there and lower limit for Solas V or does it apply to a tender of say 3 meters in length

Does it apply to all pleasure vessel power by paddles/, engine and sails

 

[Zing]

I would fit an active radar reflector, especially if on a small or hard to see yacht. The performance of the active units is Dramatically better than the passive ones, which is often just not good enough.

 

[Robin]

Nothing. My original question was is it true such a sailing vessel could only be seen on radar from 3 nm away, or is that scare mongering by someone trying to sell me radar reflectors?

My comment about 20 nm was the closest thing we have achieved to an approximation in this thread is more than nothing, but probably less than 20 nm... which as you infer isn't really of much help.

It was me that mentioned 20 miles merely to illustrate that one one occasion at least my boat sporting a mast mount Firdell Blipper was visible at that range to a land based radar presumably operated by experts.

I could also have added that previously on the same occasion a wooden Hillyard or similar ketch with wooden masts and no obvious reflector had appeared going the opposite way to us and passed within 20 metres of us, totally unseen by me on our radar and which I was watching intensely having just passed across the 'lanes' east of the Ushant TSS. it was this incident that prompted by call to Ushant re visibility in the Four which usually has plenty of small stuff and/or fishing folk around

 

[Pye_End]

Solas V apply to pleasure vessels under 150 GT.

Is there and lower limit for Solas V or does it apply to a tender of say 3 meters in length

Does it apply to all pleasure vessel power by paddles/, engine and sails

Yes, but the wording is 'if practicable'.

SOLAS V 19.2.1.7 requires vessels if less than 150 gross tonnage and if practicable, [shall have] a radar reflector or other means, to enable detection by ships navigating by radar at both 9 and 3 GHz.

 

[PaulRainbow]

Solas V apply to pleasure vessels under 150 GT.

Is there and lower limit for Solas V or does it apply to a tender of say 3 meters in length

Does it apply to all pleasure vessel power by paddles/, engine and sails

All of that is available to view online. Use your old mate Google.

 

[PaulRainbow]

Yes, but the wording is 'if practicable'.

SOLAS V 19.2.1.7 requires vessels if less than 150 gross tonnage and if practicable, [shall have] a radar reflector or other means, to enable detection by ships navigating by radar at both 9 and 3 GHz.

It'd be pretty difficult to justify that it was "impracticable" to fit one on the OPs 30 footer.

Not that i've noticed any radar detector police wandering the pontoons. But, as there is no downside and it might make you more visible, why not fit one ? There could also be cases where issues of insurance could be affected by not having one.

 

[pyrojames]

It slightly sounds as if the OP is trying to avoid being seen....

 

[Neeves]

It'd be pretty difficult to justify that it was "impracticable" to fit one on the OPs 30 footer.

Not that i've noticed any radar detector police wandering the pontoons. But, as there is no downside and it might make you more visible, why not fit one ? There could also be cases where issues of insurance could be affected by not having one.

The case against fitting one is complacency and their value in comparison with being proactive, having radar, AIS and diligent watch keeping. I'm considerably more worried about hitting a whale than a 200,000t bulk carrier but fog is not common here - unlike whales. Whales are a real nuisance as they appear to have copied yacht owners who ride the current going south and skirt the beach going north (unlike the bulk carriers, who do not skirt the beaches ).

Jonathan