Radar is now redundant ?

[kismar]

There is a very small percentage of vessels that have AIS. All of which can cause you great harm and/or great finial burden.
Also the law reads, if you have radar it needs to be on and watched. Unless it is broken.

[sck5]

GPS tells you what SHOULD be there. Radar tells you what IS there.

[MissTeak]

Different purposes and, as mentioned, not mainstream in all areas in which we travel. The fishing boat point is very much relevant! I recently read an article reporting large freighters and tankers traveling between certain South American and Middle Eastern countries actually shutdown their AIS transponder to avoid being tracked. BTW - those cruising pacific Mexico and the Sea of Cortez know well the shortcomings of charts (paper and electronic). Charts, AIS, Radar and, most importantly, eyeballs and common sense have worked pretty well for us although we have been softly aground a few times….

[requiem]

If hundreds of yards will make a difference, you might be passing too close.

Whilst the ship in this picture was visible on AIS, I thought it still relevant to the thread. We were following this ship coming in the Golden Gate yesterday, after we first heard them failing various sailboats near Pt. Diablo. I know it's hard to make out, but there's a 300m container ship (MSC Alghero) between us and the bridge:



(incidentally her antenna is positioned 227m aft of the bow and somewhat to port.)

[sck5]

"Also the law reads, if you have radar it needs to be on and watched. Unless it is broken. "

Not entirely. I had a boat with insufficient battery capacity to run radar 24/7. In that case it isnt exactly broken but it is unusable much of the time.

Modern HD radars spin up so quickly that it is just fine to turn it on when you need it but not otherwise because that would mean losing all other instruments that need battery power.

[Gerrit Coetzee]

Originally Posted by BB7

Fair point re fishing boats, thanks. Rocks are charted adequately, and radar wont find them anyway. When you are sailing at night do you rely on the radar?

Rocks are adequately carted?

That is not correct.

I don't sail at night without AIS and Radar . Like to err on the save side.

[jimellifritt]

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GPS location on a super detailed chart, and AIS streaming from every other vessel, I wonder if Radar is now an outdated and redundant technology?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 ?

cruising in Mexico, almost no local vessel uses AIS, even large commercial. in the Puget sound almost no fishing vessels turn them on. we run both daily and the radar in all limited vissibilty.

[Mike OReilly]

Originally Posted by CarlF

Every commercial boat over 65ft in the US (and Bahamas/Caribbean) is required to transmit AIS and all the big yachts transmit as it is required by their insurance companies. Smaller fishing boats often don’t transmit but they aren’t as big a collision worry as a 800ft container ship.

That's an odd perspective Carl. I think the smaller boats are a far greater worry than the big boys. It's far easier to spot a large vessel with your eyes and ears than a smaller one.

Originally Posted by CarlF

So yes, I agree with the OP that chartplotters and AIS have made radar mostly redundant. If you have the money in your budget I’d certainly install radar - especially if you do overnight passages or often cruise in fog. But for most US based cruisers radar is a “nice-to-have” not a “must have”.

The question wasn't "for most US based cruisers." This is an international forum. But again, it very much depends on where you are, and how you cruise. As I said, if you mostly travel in developed or richer area, and especially if you stick to more benign climates, then radar is less useful. But if you travel further off the beaten path you'll find a lot fewer vessels with AIS signals, and far more need to see in low-visibility times.

[Adornan]

Depends on where you sail. In some areas there are many boats without AIS, but in the developed world AIS might be enough.

Biggest value I had with radar crossing the Atlantic and Pacific was to identify the shape and progress of nearby squalls. The colours on my old raymarine radar also gave you an idea of the intensity of the squalls.

[boatpoker]

Originally Posted by Statistical

b) no longer exists and hasn't been used for 20+ years now. The DoD make a public promise to never enable it again even when it was still available (and didn't).

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.

[bclaude]

Radar can be used for weather detection such as squalls and thunderstorms with accompanying heavy rain. I often use my radar to navigate around local weather

Further redundancy is the name of the game as it relates to safety. I have had situations where I was at anchor while my chart plotter showed me supposedly 100 yards/m inland. Instruments and electronic charts are always subject to errors or defects and it is hugely helpful (and much safer) to compare similar information provided by completely indépendant systems. If they concur then you can proceed with confidence such as thick fog or other tricky situations. If you receive conflicting data, think twice before proceeding.

Lastly electronic charts can be non existant or highly unreliable in less navigated waters. In those instances you will be glad to rely on a good old radar.

[Discovery 15797]

I'll speak frankly...

If you don't currently use radar, and if you don't understand the utility that it provides that a chartplotter and AIS do not offer, then you don't need radar.

However, if you sail at night (esp. long passages), if you sail in areas of fog or heavy rain, if you sail in areas where thunderstorms occur than you should learn how to use radar and install it.

Radar, chartplotters, and AIS are all navigational tools that provide different information. Also, to assume a chartplotter is 100% accurate is as foolish as it is to assume that all boats have AIS and have it turned on.

[CyKlop]

I'm sure you've had an earful at the moment but...


One of the things I've noted is that there are many boats out there that "have AIS" when what they mean is that they have an AIS _receiver_. As such, assuming you have a full AIS transceiver, they can see you but you can't see them.


Radar tells you about things that are not transmitting:


Vessels without an AIS transmitter
Buoys
Rocks (yes, you can see some rocks with radar
Radar ranges
Shorelines


Charts are great and, like all people, I rely on them BUT, it's important to realize the number of errors that can creep in:


Do you truly know exactly where you are? It's interesting to turn on a GPS track while your boat is tied up to a wharf and see how much your boat moves. I had one track where my boat moved more than 1/2 a mile... straight inland.


Are the charts completely accurate? For the most part, yes they are, but sometimes not.


A Radar tells you where things _actually are_ in relation to your boat rather than where you think they are (for those things that the radar actually sees).

[merrydolphin]

I guess you dont do a lot of sailing in the fog. Nor track rain storms, or sail in foreign waters where even though the GPS is accurate, the charts aren’t. Not to mention the bunches of boats, and even ships in some areas that do not have AIS. Plus, the radars keep getting better and the price coming down is a winner.

Absolutely radar for me.

[tgradyv7m]

So following the initial logic, we can get rid or our depth meters now, eh? We can always use a weighted line over the side.