Radar returns, active, passive and no reflector comparison

[Iliade]

My radar is a pretty hopeless Apelco unit, but if you can get the contrast just so, it kind of works.

My question is does my active radar make me any more visible to shipping than the pretty useless tube of aluminium strung up the backstay?

P.S. Does anyone know of a modern screen that can be fitted to replace the perhaps tired original?

 

[Uricanejack]

A heretical answer:

The arguments over visibility on radar, type A/B AIS and whatever are perfectly valid in open water, but I would suggest that, for Solent pootling, they're pretty irrelevant. Any ship will be constrained by its draft anywhere I can think of, even if it doesn't have a moving exclusion zone, so there's no substitute for keeping a good lookout and being aware that that container ship you can see coming out of Southampton Water will disappear behind Norris Point then suddenly leap out to grab you just as you're wondering where it went.

I've no proof - not even any evidence, but I have a VERY strong suspicion that bean counters have done their risk assessments and decided that it's cheaper to run down an errant yottie than to park a panamax on Bramble Bank or Ryde Sands. I'm sure no one would admit that orders have been given, but I always work on that assumption. Anyway, Colregs are simple. Yotties keep out of the way of stuff that's constrained by its draft, and I'm not going to argue whether or not 10,000 tons of steel is wearing a cylinder, I'm going to bugger off sharpish long before there's any risk of collision.

I doubt bean counters would make such a calculation, and if they did the cost of an accident involving loss of life would far outweigh. The cost of a grounding.
The assessment would be made on the day, by the unfortunate bugger on the spot, who will have to answer for it. In reality the vast majority will go to great lengths to ensure such a situation never arrives in the first place. Most will complete an entire career without incident. Very occasionally mistakes or errors will be made. Or complacencies, preconceptions, or just neglectful watch keeping, will lead to accidents.

A recent court case might suggest otherwise, I would still expect 99.9 % of the time both a keen visual lookout and radar watch to be kept at all times in the Solent or La Manch. Even so I would still presume the other vessel was the 0.1% er. Until actions proves otherwise. And I am pleasantly surprised.

 

[Uricanejack]

This topic has come up a few times.

Yes I have heard of the report about radar reflectors after the Ouzo. Which contradicts my personal observations.
I would also say it’s only one report.

My observations. Radar will pick up a Shit Hawk, siting on a log on a nice day. Sail boats even kayaks will be picked up on a nice day.
So what. They can be seen on a nice day. The concern is on crappy days when the weather is not nice.
As a breeze picks up, the sea state picks up, or rain starts the radar picks up every wave, and many of the rain drops obscuring everything with clutter.
The radar it gets adjusted t reduce this clutter. If over adjusted even large ships, island or continents can be obscured.

This adjustment, can be done by the operator or automated. It varies with the range scale in use and the type of radar, X or S band

In most conditions a small sailboat will be quite easily detectable by a diligent observer on a proper tuned and set radar.

Fortunately restricted visibility usually coincides, with relatively light winds and a lack of rain. Setting a radar to pick up even small poor targets is quite easy. The Shit Hawk on a log, kayaks, small sailboats or other vessel, particularly if fitted with radar reflectors, should be detectable as good targets at a reasonable range.

Rain, particularly heavy rain, can seriously affect visibility and radar. Correctly adjusting the radar becomes more difficult and both the visual lookout and radar observations require greater diligence. Small vessels may often be picked up visually before they are picked up by radar.
A sea states increase the visibility may or may not be affected, visibility is usually not affected until conditions start to get extreme. Even so even relatively large vessels may be lost to view both visually and by radar between wave crests. Against n both visual lookout and radar observations require more diligence.
Visual lookout may often detect other vessels prior to radar.

Experienced watch keepers prioritize visual lookout over radar. Even so both are used in conjunction to enhance the other.
I have posted this before. As the weather deteriorates S band or 10 cm Radar out performs X band or 3 cm Radar by a significant margin.,
In the past it was common for ships to carry only S or X band particularly X band. Most probably have ither two X band or more probably one of each X and S band.
The S Band is usually the big scanner at the top of the mast. The X band the smaller scanner lower down.
One may be being prioritized by the watch keeper. Depending upon location and conditions.
Why?
different bands have different advantages,
X has better definition and is often preferred for navigation.
S has better target detection and is often preferred for collision avoidance.

Ideally both should be in use, and monitoring of both along with visual lookout should be ongoing.
This should include the use of radar plotting which today will almost certainly be by ARPA and carried out automatically.

Having said all this, even though I believe under most conditions, most of us will go sailing in, most of our vessels will be quite easily be detected by radar with or without additional fittings.

I believe based on my observations, Radar reflectors significantly improves the likley hood you will be seen by a diligent radar observer.
A good set of Navigation lights greatly improves the likley hood you will be seen by a diligent watch keeper.
I have both fitted on my boat.
They are both required, I would fit them any way.

Is an active radar reflectors worth while? will it improve you likely hood of being detected by a diligent observer? I don’t know. Probably. Is it worth the cost? if it makes you happy and you can afford it why not,
Apparently the don’t work with S Band. So stand alone doesn’t seam like a cunning plan to me. Even though some posters suggest regular radar reflectors don’t reflect S Band. I’m not convinced they don’t help.

AIS a receive only doesn’t do much for being seen. A transponder certainly helps, and has the significant advantage of being detected round corners. Which when you have corners can be helpful. I would suggest it doesn’t replace good lights and a reflector just enhances you detectability.

What if you happen to encounter a less than diligent watch keeper or radar observer.
None of the above will help.
As for the Ouzo. Clearly the watch keeping, was less than ideal.

Best to keep a diligent lookout your self. JIK

 

[Ohlin Karcher]

Echomax offer a combined X and S band RTE.
Since I fitted my X only version 4 yrs ago, no ships have given any concerns, and if you are wondering, AIS or RTE? I would say, all ships and watchkeepers use the radar all the time but many watchlkeepers may not be able to use the AIS properly, and it is the definition of 'rubbish in, rubbish out'v but they will all be familiar with radar and usually X band except out at sea.
Echomax offer X, X+S, but no S only versions..
sorry for the typos but the carp new forum wont allow corrections without wiping the whole post

 

[Mistroma]

One of my early experiences in using my now old JRC RADAR is that it works well if it's on the correct range and tuned correctly.
Back in about 2002 I came back into Poole harbour solo on a dark foggy night. At that time I didn't know the buoyage layout well and it was pre Chart Plotter so I had the RADAR on on short range and the chart to hand. I could pick up boats on their moorings, the channel buoys and markers for the small ships channel which I could follow without a problem.
I have an octahedral reflector at the top of the mizzen and for peace of mind in my early days with this boat I have called up the ferry on X channel passages to ask if I was visible on their RADAR, I was, but I'm still not sure if it's the reflector or the fact that I have two aluminium pole pointing skyward and two laying horizontal!
I wouldn't give you tuppence for those so called reflectors that look like a neon tube and I am suspicious of some of the ones that look like fenders, you just don't know what is inside them. Maybe I'm just an old cynic.

I had a very early tiny green screen radar, possibly JRC, back in the late 80s or early 90s. I remember finding and entering Findhorn in pea-soup fog with only the RADAR to help. My initial plan was to aim well West, turn East as I reached shallower water and try to find the buoy about 0.75nm off the entrance. However, the buoy was easily spotted on RADAR from well offshore. I could actually see the small channel buoys on radar and was able to motor right up the middle of the very narrow channel. It was a surprise because the "channel buoys" were just small spherical plastic buoys about a foot in diameter and 1/3 under water. It was a dead calm and, to my complete surprise, they showed up easily on the screen. No chance if there had been any waves at all. I'm lucky that there weren't a load of seagulls sitting on the water as they'd have given a larger echo.

 

[Babylon]

It doesn't matter what you're carrying to make yourself more visible: if they're not looking they won't see you.

Single-handing back from Alderney in perfect visibility and slight sea-state in a steady SE3, the AIS was showing a quarter-mile CPA with a container ship on our port bow. Unhappy with the situation but not wanting to alter course too early as this would have put us into problems with other vessels also heading east, I used the VHF to call him - merely to ensure that he was aware of our presence.

This was news to him! We hadn't shown up on his radar (27ft yacht with Tri-Lens passive reflector), nor had the bigger yacht astern of us. I repeated my position, both as a lat-long and as 2.25NM SE of his current position, but he still couldn't find us on the screen. When I asked him if he could physically see us out the window, the answer was still negative!

Satisfied however that everyone listening in knew we were there, I slowed and altered to go under his stern, as did the bigger yacht who had by this point overhauled me - in picture below.

 

[dom]

This topic has come up a few times.

Yes I have heard of the report about radar reflectors after the Ouzo. Which contradicts my personal observations.
I would also say it’s only one report.

My observations. Radar will pick up a Shit Hawk, siting on a log on a nice day. Sail boats even kayaks will be picked up on a nice day.
So what. They can be seen on a nice day. The concern is on crappy days when the weather is not nice.
As a breeze picks up, the sea state picks up, or rain starts the radar picks up every wave, and many of the rain drops obscuring everything with clutter.
The radar it gets adjusted t reduce this clutter. If over adjusted even large ships, island or continents can be obscured.

This adjustment, can be done by the operator or automated. It varies with the range scale in use and the type of radar, X or S band

In most conditions a small sailboat will be quite easily detectable by a diligent observer on a proper tuned and set radar.

Fortunately restricted visibility usually coincides, with relatively light winds and a lack of rain. Setting a radar to pick up even small poor targets is quite easy. The Shit Hawk on a log, kayaks, small sailboats or other vessel, particularly if fitted with radar reflectors, should be detectable as good targets at a reasonable range.

Rain, particularly heavy rain, can seriously affect visibility and radar. Correctly adjusting the radar becomes more difficult and both the visual lookout and radar observations require greater diligence. Small vessels may often be picked up visually before they are picked up by radar.
A sea states increase the visibility may or may not be affected, visibility is usually not affected until conditions start to get extreme. Even so even relatively large vessels may be lost to view both visually and by radar between wave crests. Against n both visual lookout and radar observations require more diligence.
Visual lookout may often detect other vessels prior to radar.

Experienced watch keepers prioritize visual lookout over radar. Even so both are used in conjunction to enhance the other.
I have posted this before. As the weather deteriorates S band or 10 cm Radar out performs X band or 3 cm Radar by a significant margin.,
In the past it was common for ships to carry only S or X band particularly X band. Most probably have ither two X band or more probably one of each X and S band.
The S Band is usually the big scanner at the top of the mast. The X band the smaller scanner lower down.
One may be being prioritized by the watch keeper. Depending upon location and conditions.
Why?
different bands have different advantages,
X has better definition and is often preferred for navigation.
S has better target detection and is often preferred for collision avoidance.

Ideally both should be in use, and monitoring of both along with visual lookout should be ongoing.
This should include the use of radar plotting which today will almost certainly be by ARPA and carried out automatically.

Having said all this, even though I believe under most conditions, most of us will go sailing in, most of our vessels will be quite easily be detected by radar with or without additional fittings.

I believe based on my observations, Radar reflectors significantly improves the likley hood you will be seen by a diligent radar observer.
A good set of Navigation lights greatly improves the likley hood you will be seen by a diligent watch keeper.
I have both fitted on my boat.
They are both required, I would fit them any way.

Is an active radar reflectors worth while? will it improve you likely hood of being detected by a diligent observer? I don’t know. Probably. Is it worth the cost? if it makes you happy and you can afford it why not,
Apparently the don’t work with S Band. So stand alone doesn’t seam like a cunning plan to me. Even though some posters suggest regular radar reflectors don’t reflect S Band. I’m not convinced they don’t help.

AIS a receive only doesn’t do much for being seen. A transponder certainly helps, and has the significant advantage of being detected round corners. Which when you have corners can be helpful. I would suggest it doesn’t replace good lights and a reflector just enhances you detectability.

What if you happen to encounter a less than diligent watch keeper or radar observer.
None of the above will help.
As for the Ouzo. Clearly the watch keeping, was less than ideal.

Best to keep a diligent lookout your self. JIK

Excellent post. Re active transponders, you’re right that some work only on X-Band, but others operate on both X- and S-Bands. I agree with you that using an ‘X- only’ transponder is seriously deficient for the reasons you say. BTW extensive testing suggests that the active transponders work as claimed and they perform much better than passive.

Re S-Band/Passive; tests have shown that some including the Echomax 230 produce a weak return on S-Band, but as you say most passives operate firmly in S-Band stealth mode.

 

[johnalison]

My radar is a pretty hopeless Apelco unit, but if you can get the contrast just so, it kind of works.

My question is does my active radar make me any more visible to shipping than the pretty useless tube of aluminium strung up the backstay?

P.S. Does anyone know of a modern screen that can be fitted to replace the perhaps tired original?

This question is often asked, and the answer is no.

I would imagine that a replacement screen would cost more than getting a new set. If you are intending to do the kind of sailing where radar would come into use, why not get a new set anyway. Even without the fancy new technology the view would be enormously better. While you are about it, you may as well combine it with a plotter and AIS, active and passive, to make the whole system work effectively. It's only money.

 

[Yellow Ballad]

This is going to sound like a silly question but does a radar system on your boat improve you visibility to others? Does it ping back so to speak like a Seeme/RTE or just allow you to see what's out there, as in just a reciever of your own waves?

I've only ever played with it once on a friends boat, I've always thought I didn't need it and favoured an RTE instead but I'm slowly coming round to the idea as it's not a huge amount more.

 

[dom]

My question is does my active radar make me any more visible to shipping than the pretty useless tube of aluminium strung up the backstay?

The answer is transmitting will indeed increase your visibility to other vessels - but only to warships!

 

[lw395]

This is going to sound like a silly question but does a radar system on your boat improve you visibility to others? Does it ping back so to speak like a Seeme/RTE or just allow you to see what's out there, as in just a reciever of your own waves?

I've only ever played with it once on a friends boat, I've always thought I didn't need it and favoured an RTE instead but I'm slowly coming round to the idea as it's not a huge amount more.

Other people's RTE's will indicate when they are painted by a radar.
Your radar won't be seen by other people's radar.
In Electronic Warfare situations, they might have a radar warning receiver or an anti-radar missile to receive your signals...

 

[Yellow Ballad]

Thought that may be the case.

So what out of interest does a RTE is send out to enhance the the target?

 

[dom]

So what out of interest does a RTE is send out to enhance the the target?

Try this link to Echomax:

FAQ for EchoMax Radar Reflectors

 

[Seven Spades]

One of the magazines did am amazing group test a few years ago and they reached the following conclusions:-

1. Tube reflectors are simply useless.
2. The big Echomax attached to the mast was the second best
3. The winner was SEE ME

 

[Graham376]

I've only ever played with it once on a friends boat, I've always thought I didn't need it and favoured an RTE instead but I'm slowly coming round to the idea as it's not a huge amount more.

SEE ME and passive reflectors are fine if the other vessels are using their radars but useless if not. Your radar tells you what's around you, not just other vessels and if coupled to gps will show you which of the targets is the channel buoy you entered as a waypoint and not one of the moored boats nearby, this is good at night or reduced visibility. Using the ebl on a moving target tells you whether there's a risk of collision or not, much the same as using a compass to see if the bearing changes.

 

[Babylon]

Why assume anyone is looking?

 

[Iliade]

Thanks, I'll just keep the steamer-scarers in date then.

 

[Graham376]

Why assume anyone is looking?

I always assume they're not looking. As well as assuming that other ships will see them on radar, many seem to think AIS will keep them safe but that's very often not true. Large vessels can filter out class B and I never see anyone transmitting as, in common with thousands of other small boats, don't have a receiver.

 

[GHA]

Why assume anyone is looking?

Cos they say they see me Or generally behave that way. The big boys seem to be very professionally run ships keeping a good watch by all available means, unlike a lot of the WAFIs out there.
Though good practice not to assume that *everyone* is looking.

 

[Ohlin Karcher]

Why assume anyone is looking?

Obviously you can assume that the vast majority of vessels are looking, or it woulld be chaos.
I have never knowingly not been seen, or even concerned, by any ship's behaviour (except ones I was crewing on ) .
They take pride in getting things done prpperly and have just as much concern for their fellow man as you do.
That said, radar is 100 times more likely to be used properly on the average ship than AIS, so an RTE is the way to go.
I sometimes wonder, when a yachtperson says they often have edgy incidents with ships, if it was the yacht who helped cause it , eg by not standing on unpredictably?

If I was going to fit radar on a cruising yacht, I would choose FM radar for various good reasons.