Radar in 2020

[powerskipper]

I trained on radar...a while ago. I just (finally) bought a boat with a radar set which is functional but pretty old and not up to modern standards, it's at the chart table so useless for short handing and doesn't interface with the outside world so won't show anything on my plotter at the helm until I select a target.

Long story short I need some upgrades, and budget isn't necessarily the main driver.

The new boat has enough windage as it is and I'm wondering whether radar adds enough benefit to justify the extra plus power draw plus expense. What is radar really giving me if I implement AIS? I get that before AIS it was awesome, been there and lived it. But in 2020? What does radar offer the smaller boat that AIS doesn't? AIS will more consistently spot any boat I really care about plus a few others I don't. AIS isn't what I consider optional so it will be there whether radar is installed or not.

I guess the real question is, am I upgrading radar just because it's already there and I like toys? If you didn't have it already, would you fit it to a new <40' yacht?

AIS is great for seeing big stuff but it is updated by the ship for detail and can take up to 5 minutes to refresh the position
Radar shows you what is there as long as it sees it. At a longer range it may not see smaller object clearly depending on the set you use.

 

[ashtead]

If you encounter a us navy fleet in the med at night steaming toward you it might not show on ais but makes a clear enough sight on radar even if no light glow is visible.

 

[DJE]

The boat came with a radar at the chart table similar to that described by the OP. We have replaced all the electronics including AIS and a plotter at the helm. But for now we've kept the old radar.

In fog it works well with two of us - one at the chart table and one at the helm. There is another plotter at the chart table so it is fairly easy to compare AIS and radar there. There's not much to see on deck in fog anyway! And when approaching a drying harbour entrance in very thick fog a couple of years ago it was great to see the piers on radar rather than relying entirely on GPS.

 

[jac]

I would also add that modern radar is a country mile ahead of the old stuff. I did the RYA Radar course and whilst it was useful the lecturer did spend some time on the difference between new and old - basically it is more efficient, higher definition but you do lose range. I would fit a modern set on any new boat - it's a couple of grand but is accurate enough to reliably pick up piles in a river. That could be handy!

 

[westhinder]

If you encounter a us navy fleet in the med at night steaming toward you it might not show on ais but makes a clear enough sight on radar even if no light glow is visible.

Crossing Biscay two years ago we saw a NATO fleet on an exercise, big aircraft carrier, several associated ships, none of them transmitting AIS. A couple of hours later, when it was dark, we sailed into thick fog. Knowing that several ships were around not showing up on AIS was not a comforting thought, but our radar provided very welcome reassurance that we were not going to bump into them or into fishing boats not transmitting AIS.
I’m a huge fan of AIS, but it does not replace radar.

 

[prv]

I would also add that modern radar is a country mile ahead of the old stuff.

Definitely agree. Ariam had the classic C-Series radar when we bought her, which was ok, got us out of a tight spot between Chaussey and St Malo, and was helpful a few other times. But all it did was draw fuzzy yellow pictures, needing manual interpretation.

The plotter eventually died, and we replaced the whole system with the current Quantum radar and Axiom plotter. It's a vast improvement. Last summer we left Cherbourg into unexpected fog, and then shortly afterwards the AIS receiver went mad. I later found it was emitting long streams of random characters instead of discrete AIVDM messages. Managing the shipping lanes with the old radar would have been hard work, and being honest as an unpracticed operator there'd have been a fair bit of trusting to luck and/or the ships' own radar watch and response as I doubt I'd have kept up with all the ships or plotted them all accurately. With the modern radar, whose target-tracking software actually works, we could designate targets and then let the computer keep track of them all, generating course, speed, CPA, predicted intercept, etc just as you would get from AIS. Not quite as accurate, being synthesised from radar returns rather than transmitted directly, but perfectly good enough to let us handle the lanes with confidence despite never making visual contact with anything from the Cherbourg breakwater to the Needles fairway buoy.

I've since replaced the faulty AIS receiver with a transmitter, but I'm also now both more confident in the radar and more convinced of its importance.

Pete

 

[johnalison]

Desirable though a modern radar is, in the open sea almost any radar is vastly better than nothing. I don't myself use MARPA although I have it, since AIS does the same thing much better, but setting a bearing line is simple enough, and I also find wakes useful when there are multiple echoes. All I hope is that I don't encounter a stealth vessel with a lazy watch officer.

 

[38mess]

I like to have radar aboard, a few years ago we were out in the Bristol channel at night in bad Vis and the radar picked up a large coaster coming at us on the wrong side of the channel at 15 knts. No sign of him on AIS and he was not answering the radio, we kept out of his way.
Also I think warships can turn off ais although not sure of they.

 

[johnalison]

I like to have radar aboard, a few years ago we were out in the Bristol channel at night in bad Vis and the radar picked up a large coaster coming at us on the wrong side of the channel at 15 knts. No sign of him on AIS and he was not answering the radio, we kept out of his way.
Also I think warships can turn off ais although not sure of they.

I found that in the Baltic German coastguard vessels transmitted on AIS. This was useful if one was a bit tardy in setting up a motoring cone.

 

[Graham376]

We've found radar very useful and wouldn't be without it. Has made the difference between going or not going when fog around and shows the many boats not transmitting AIS, (which I haven't bothered fitting). Those who rely on plotters in fog in unfamiliar waters should remember that buoys, fish farms and other obstacles may well have moved since the chart was last updated.

 

[duncan99210]

Radar and AIS are doing 2 separate but related tasks. AIS is providing position, course and speed information on named vessels: which is great but relies on vessels transmitting an AIS signal. By no means all vessels which are required to transmit do so and there are plenty of vessels too small to be required to transmit AIS out there.
Radar not only detects other vessels, it will also show you the land. I’ve made approaches in the dark where the plotter was a great reassurance but the radar was much more helpful in determining where the land and other obstructions were: their echos stood out well: that wasn’t using an overlay just the radar screen.
In busy areas, AIS is useful but in poor visibility radar is the real game changer. I was once caught out by a fog bank off southern France: the AIS was largely blank but there were up to 20 odd small craft echoes round about us, some of them moving at 20+ knots. It would have been a very unpleasant experience except for the radar, which enabled us to shape a course to avoid the other vessels.
Whilst I don’t use the radar frequently (I tend to avoid the type of weather where it would be useful) it is regularly tested. I often engage the MARPA to check that my estimation of what a vessel is up to is correct. My system is fairly ancient now and will need replacing before too long: radar will be part of that replacement as I wouldn’t be happy making longish trips without it.

 

[laika]

I guess the real question is, am I upgrading radar just because it's already there and I like toys?

Well someone has to give a (slightly) contrary view.

Like yours, my boat came with a green-screen radar at the chart table. It was pretty power hungry and I never turned it on except to test it was working. Moreover the big steel guard at the cross trees which had been installed to stop the genoa catching on the scanner interfered with the pole uphaul so when the mast was down I just took the whole lot off.

I'll argue that an old green screen at the chart table is of limited use to the yachtsperson who sails short handed with someone less experienced. Without arpa you need to be below decks and plotting for it to be any use for collision avoidance. With a novice on the helm I probably want to be above deck with my ears open in fog. I did the RYA radar course 15 years ago but a recent thread on radar assisted collision and subsequently trying to fully grasp what went wrong in the Andrea Doria disaster made me realise how easy it is to forget how to plot properly (knowledge gap now re-plugged . Modern radar with target tracking and chart overlay is a different proposition but despite plans to I haven't replaced the old radar. Why?

I've not needed it. AIS has been a game changer for channel crossing and gives me all I need in good vis. As a leisure sailor I have no desire to set off into fog. I'm well aware from personal experience of how a channel fog can descend when not forecast, but I haven't crossed the channel in spring in my current boat. Yes I've been caught out in swathes of mist round cap de la hague on a bright, sunny summer's morning: I would have used a modern radar if I'd had it but the very few times radar would have been beneficial to the type of sailing I've done recently doesn't make it a necessity. Would it be handy crossing traffic if my AIS failed? Sure, but it's no cop if the plotter fails and given it's only a real issue in fog which I try to avoid, it's a risk I can accept. Is it still handy for position plotting? Of course but the ubiquity of GPS has made that a whole lot less critical than it was 25 years ago.

And radar poles are ugly and a scanner on my mast will likely interfere with the pole-up

But still I probably would have bought a quantum but my 2012-ish purchased C90W won't work with it so I'd have to replace the (perfectly functional) plotter, and the new raymarine plotters don't have Seatalk-1 inputs so I would have had to buy a converter (I've since bought one anyway). The proprietary binding of scanner to plotter is a PiTA. I understand there's an NMEA OneNet working group to create a standard for radar interfacing via OneNet but of course OneNet is 8 years overdue with no products on the horizon.

I'm not arguing against any of the traditional "why you want radar" arguments. I am saying that depending on the type of sailing you do it might not be the most vital bit of kit and in current implementations it's currently a product with built in obsolescence . Leave it until you've decided you do need it and it may be more interoperable and future-proofed (but that could be a long wait, so if you do think you need it...).

 

[peter gibbs]

I trained on radar...a while ago. I just (finally) bought a boat with a radar set which is functional but pretty old and not up to modern standards, it's at the chart table so useless for short handing and doesn't interface with the outside world so won't show anything on my plotter at the helm until I select a target.

Long story short I need some upgrades, and budget isn't necessarily the main driver.

The new boat has enough windage as it is and I'm wondering whether radar adds enough benefit to justify the extra plus power draw plus expense. What is radar really giving me if I implement AIS? I get that before AIS it was awesome, been there and lived it. But in 2020? What does radar offer the smaller boat that AIS doesn't? AIS will more consistently spot any boat I really care about plus a few others I don't. AIS isn't what I consider optional so it will be there whether radar is installed or not.

I guess the real question is, am I upgrading radar just because it's already there and I like toys? If you didn't have it already, would you fit it to a new <40' yacht?

You kmow tbe answer. Radar shows you evverything out there - harbour walls, cliffs, buoys and boats. AIS only tbe last one. No contest.

PWG

 

[TernVI]

I think this bloke had radar:
Cowes ferry yacht-crash captain 'lost control in fog'

Radar is a wonderful thing, but very few people are actually very good at using it.
Mostly they look at the display and mentally force it to agree with the chart image.
Most yachtsmen get virtually zero practice at actual collision avoidance by radar, which is really quite hard.

 

[Graham376]

Most yachtsmen get virtually zero practice at actual collision avoidance by radar, which is really quite hard.

Why? First thing we did was to play with it in daylight to see how different targets appeared and moved and what the various filters and gain did. Haven't had to use it in anger for a couple of years now but still switch it on occasionally to keep in practice.

 

[johnalison]

I think this bloke had radar:
Cowes ferry yacht-crash captain 'lost control in fog'

Radar is a wonderful thing, but very few people are actually very good at using it.
Mostly they look at the display and mentally force it to agree with the chart image.
Most yachtsmen get virtually zero practice at actual collision avoidance by radar, which is really quite hard.

While not denying the usefulness of proper radar training, I have found that it can still be used effectively at a simple level. Providing you are consistent about orientation, the screen is not hard to interpret, and echo is either there or it isn't. For collision avoidance, the process is not much different from that using a visual contact, in that a constant bearing indicates a risk. For the most part, I just use a bearing line and watch the return move. If I have spare time, as when motoring in calm water, I will play with plotting vessels' positions and trying to work out their speed and course, but this doesn't add much to my assessment.

I haven't used AIS other than my own Raymarine set, but there can be misjudgement even there. Apart from obvious errors, such as the know time delays, my usual policy is to set a 10 minute vector on vessels. When seen on the screen, it is important to note that this is displaying the vessel's vector on the chart and not relative to my boat. Getting this wrong could lead to an AIS-assisted collision.

 

[lustyd]

@laika thanks for your contrary view. I think you understand my thinking and put similar thought into it which I appreciate in this echo chamber! Thanks also to everyone else with the more standard responses, many of you helped me to see where the real value lies in radar. To me it's not in the standard "see the coast, boats, buoys etc." as AIS and plotter really do give me that sufficiently for the normal type of smallish boat sailing I do. It's more in the direct nature of radar and that it provides a sort of new vision as opposed to more information. I'll certainly be upgrading it next year with a screen indoors and out

 

[chubby]

Interesting thread; I am going through the annual pondering of replacing an old stand alone furuno 1621 which is course up with a new quantum radome which will link to my axiom plotter and give north up overlay! the furuno is ancient and i keep hoping it will make the decision by dying gracefully. What would be a pain is for it to give up mid season.

 

[TernVI]

Interesting thread; I am going through the annual pondering of replacing an old stand alone furuno 1621 which is course up with a new quantum radome which will link to my axiom plotter and give north up overlay! the furuno is ancient and i keep hoping it will make the decision by dying gracefully. What would be a pain is for it to give up mid season.

And when the GPS has a little glitch, and the 'north up' on the radar is a few degrees 'deviated', you're sailing short handed, how much experience will you have in decyphering the blobs on the screen?
It's all very nice when the navaids all agree with one another, but it's not always like that.
Sometimes it's safer to know that you're lost?

 

[pvb]

And when the GPS has a little glitch, and the 'north up' on the radar is a few degrees 'deviated', you're sailing short handed, how much experience will you have in decyphering the blobs on the screen?
It's all very nice when the navaids all agree with one another, but it's not always like that.
Sometimes it's safer to know that you're lost?

"North up" takes its reference from a fluxgate compass normally, not the GPS.