Radar is now redundant ?

[iduff]

Originally Posted by rslifkin

AIS and radar both serve somewhat different purposes. Depending on the situation, each one can tell you information the other can't. Radar and a chart also don't provide the same information.



Basically, radar tells you about objects that aren't charted or broadcasting AIS. AIS tells you more info than radar for stuff that's broadcasting. And a chart is the "what's where" base layer to work from.

"... each one can tell you information the other can't..."

This. 1000% this. Redundancy, belt and suspenders.

[Scorpius]

Originally Posted by sv_pelagia

But apparently we're some sort of "edge case".
..

Oh, I think we are. I think I read somewhere that we are one of the six most challenging areas in the world to cruise. My experience has been that, generally, if you avoid hurricanes, the tropics and sub-tropics are much easier. I remember sailing to the north end of the Sea of Cortez. We were alone. Nobody else would brave the tidal ranges and currents - which are similar to around here but without the rapids.

[nonav]

Originally Posted by GrowleyMonster

Definitely NOT redundant. Complementary, actually. Have you ever seen a floating shipping container with AIS? Or a longline bouy? Lots of small or recreational vessels have no AIS. Best case, have radar AND AIS AND electronic chart display. With a stabilized display you can have acquired radar contacts superimposed on your ECDIS along with AIS contacts, so you get all that data in one display. Combine that with the Mk.1 eyeballs with binocular assist, and you have the full package.

Certainly it can be understood that one might want to forego the expense of a radar set, but even cost is not a great obstacle. There are systems that are pretty darn cheap that are suitable for small yachts, and they are pretty easy on the juice, too, so if you have a reasolably big bank you don't need to run the diesel or the genset to run the radar. Many users keep it on standby and power up only when required or every 10 minutes or so.

I would almost say that radar is more important than AIS, actually. Where full AIS is a really essential tool is when you are around a lot of ships or tug and barge traffic, oilfield supply or crew boats, etc and you want to be seen by THEIR AIS system as well as see them on yours. Around only other recreational and fishing vessels, where many do not even have AIS receivers, not so important and Radar will be the more useful. But again, having both is great. Sort of like having both HF SSB and Satellite comms. One doesn't cancel out the usefulness of the other. They are complementary.

Well said, and was what I was attempting to get at.

Thank you!

[nonav]

How have you found RADAR to be inaccurate?

Our old Furuno shows stick markers, small birds sitting on the water, high flyers and rarely misses an return from any target.

When running 16 kts at night quite often, I am glad it’s on the boat!

The newer Furunos, like the TZT touch II or III are really fantastic, though not inexpensive.

[FULLCIRCLE331]

I always have my radar on with a guard zone. Warnings when ever something approaches the boat. Can track storms. Can spot ATONs. On Long Island Sound some times AIS is overwhelmed so many signals the display screen is blocked out, too many boats with transmitting AIS.
My radar even spots large lobsters pot floats.

[Icarus]

Originally Posted by Mike OReilly

In my travels, there are far more boats out there without AIS than with. Maybe if you're only in rich, urban areas, it might make sense to ditch the radar. Not so in most of the rest of the world.

Besides, AIS doesn't see through fog. It can't track storm cells or fronts. It doesn't show most nav. aids.

And on top of that, I would never rely solely on a chart plotter to know where you are. A chart plotter is a projection of your location that is at least twice removed from reality. It's a great tool, as is AIS, but everyone should understand their limitations.

Well said

[Icarus]

Originally Posted by BB7

With a large screen displaying GPS location on a super detailed chart, and AIS streaming from every other vessel, I wonder if Radar is now an outdated and redundant technology?
I have radar, but very rarely use it since the GPS chart is better.
Will soon be speccing up a new boat, and wonder if Radar is worth having.

Thoughts from your experience ?

I entered New Caledonia and the GPS put me right on top of Amédéé light house.
Relying on a chartplotter can be risky.
A radar gives you real time info.

[warren2]

when we were sailing back to Turkey from Gib, off Tunisia, we saw 4 very dangerous water spouts. We could track their movement and alter course to avoid them. It was at night. We even turned around at 1 point for about 30 mins. If it saves your life or even boat damage 1 time its worth it

[goboatingnow]

Originally Posted by boatpoker

Going through Hampton Roads one week after 911 all my electronics (autopilot, depth sounder, vhf, GPS, SSB) started producing cluttered nonsense til we were well south of the Navy Ships. Not too long after that the same thing happened as we neared Naval Air Station Jacksonville. We all know the value of government promises.

Your radar wouldn’t work there either


Newer block IIF gps birds don’t even have SA ability at all

And GNSS systems like Galileo don’t even have the technology at all. Most GNSS system now read all four GNS systems and can correct between each of them.

[SVSilhouette]

Radar has many purposes:
Navigating in the dark, up rivers and thru channels with obstacles close and far.
GPS and AIS can’t show you the half sunk barge, or the corners of a bridge span or the channels markers that are off station because of a recent storm or the young lady fishing in her little skiff off that off station channel marker in the mist.
Radar is a primary navigation tool. This question highlights how lazy and unsafe people have become in navigation. Along with lack experience and education in navigation. GPS has caused us to be pretty comfortable with little to no experience. Electric charts have added to the ease of navigation and the lack of true education in navigation. I would say this has lead to more accidents and not less.
Radar uses Doppler shift to determine distance to objects.
The signal bounces off of the object ahead and returns with giving you distance and shape and mass of the object. We once used radar as a primary navigation tool, collision avoidance tool and a storm forecasting Tool.
But all tools are useless if you do know how to use them.
AIS is an excellent tool for telling everyone around you where you are and Sharing your speed distance as well. AIS cannot tell you where some one is up ahead of you is fishing, trawling, dead in the water anchored or even aground that doesn’t have it on or doesn’t have it at all.
In my experience all over the Caribbean and pacific or Hong Kong or japan Australia, Straits of Malaka basically I have navigated every ocean and never saw small fishing boats with AIS... so with out Radar you would potentially collide with every one of them.
GPS is a great navigation tool but little do people know it’s only as good as the charted datum which might have been last updated in the 1700’s
Electronic charts are getting better but once again cannot show you if a charted obstacle has moved due to recent storms...just try sailing into St. Augustine Florida using your electronic chart and see how long before you run aground.
In short every sailor who does more than day sailing on a lake needs Radar and needs to know how to use it. I am assuming that’s all of us because this is a cruisers forum. Be safe out there
SvSilhouette.net

[ranger58sb]

Originally Posted by BB7

With a large screen displaying GPS location on a super detailed chart, and AIS streaming from every other vessel, I wonder if Radar is now an outdated and redundant technology?
I have radar, but very rarely use it since the GPS chart is better.
Will soon be speccing up a new boat, and wonder if Radar is worth having.

Incorrect assumption.

Around here, probably 95% (or more) of boats do NOT/NOT have an AIS transmitter.

AIS good, replace RADAR, not.

-Chris

[SVFaith]

Whole heartedly agree that they are complimentary tools not a replacement one for another. AIS is rarely added to smaller boats that are a concern... certainly around harbors, where radar will overlap. Radar is much improved in recent years with regards to capabilities and sensitivity and reduced power draw. I cant count how many storms I've avoided by altering course based on a radar image.

[mabowers]

Originally Posted by SVSilhouette

Electronic charts are getting better but once again cannot show you if a charted obstacle has moved due to recent storms...just try sailing into St. Augustine Florida using your electronic chart and see how long before you run aground.

[emoji106]
Exactly. Leaving St. Augustine shortly after Dorian, channel markers had moved. We left at dusk and without radar it really could have been dangerous. As it was, I got closer to a Nun buoy than I want to again. Freaked my wife out...

[Ozbullwinkle]

BB7 - It seems like you are not aware that by NOT using your radar you are in breach of the Collregs.

Rule 7 : Risk of collision
a. Every vessel shall use all available means appropriate to the prevailing circumstances arid conditions to determine if risk of collision exists. If there is any doubt such risk shall be deemed to exist.

b. . Proper use shall be made of radar equipment if fitted and operational, including long-range scanning to obtain early warning of risk of collision and radar plotting or equivalent systematic observation of detected objects.

Radar is an AID to navigation and its use today is mandatory and essential. The Radar should be used so long as it is functional to warn the watch keeper of the danger in as great a time interval as possible. This implies that the Radar has to be used for long range scanning to detect the ships and do a radar plot to determine whether the ship would pose any hazard or not.

Should you have a collision with another vessel or an object your insurance company could ask you a LOT of questions as to why you were not able to avoid this collision through the use of your onboard radar in line with Collreg requirements & thereby deny your insurance claim.

A lot of recreational boat owners are not aware of the Collregs & have never read them but I strongly recommend everyone to do so. As a Commercially qualified mariner myself they are a very integral part of our training & certification & are referred l to constantly.

[Bycrick]

Minor corrections.
"Radar uses Doppler shift to determine distance to objects"
No it doesn’t. Pulse radars measure the time required for the pulse to be reflected. Doppler shift has nothing to do with it. CW radars use a variable frequency transmitter. Measuring the difference between the sent and received frequency gives a measure of distance.

Interpreting Doppler shift can give an indication whether the target range is closing or opening.

There might be military radars that can yield information on shape and size, but I doubt any small boat radar will.