AIS INSTEAD of radar?

[Suijin]

Agree with everything said so far. I have both, use both and would not give up either one.

That said, the need for one or the other is a function of where and how you use your boat. In familiar coastal waters radar might not be that important. In remote areas with sparse boat traffic, AIS doesn’t provide much value.

[Cpt Mark]

My boat did not have radar when I bought it. On the W coast of the U.S. fog is an issue and going in at night can be tricky so radar is a must. The difference in price between a stand alone radar and one that came with a fancy MFD wasn't very much so I bought the MFD version which I added forward scan to as well. I really like it much better than I thought.

As an added bonus, it has MARPA and all the features of the tricked out AIS units like Vespar which does have the best reputation out there. I bought the least expensive AIS transceiver I could find. No bells, no whistles. The MFD has them all, I just needed the signal in/out.

AIS was $500. A bit of an expense but so worth it. When cruising around Vancouver island last summer I could see the cruise ships flying towards the same narrows we were going to even though they were 2 bends back behind us. Radar wouldn't pick them up, AIS gave me all the info. AIS is awesome if everyone around you is also transmitting but it's still new enough that many don't. Have both.

[S/V Alchemy]

Originally Posted by AedanC

AIS wont show you the coast or a reef.


They are really quite different things that compliment each other rather than replace each other. Depending on what type of sailing you do and how much other traffic there is around in your area either one could be more important. We have both and I'd replace either if it failed.


The Vesper stuff is well made, we have the XB6000 and are well pleased with it.

^^^This. They are complementary technologies, not substitutes. I love my Vesper XB-8000 and it feeds accurate AIS target data to my plotter and radar (a Furuno 1815) unit over separate parts of my NMEA network. I have a separate antenna for it and it works like a charm. But on the Great Lakes, most recreational traffic has neither AIS nor radar, so in fog, and with plans to head to the Atlantic this summer, we need both.

One handy aspect of AIS is that you may be "seen" by commercial traffic as an AIS target (with all the useful info on COG and SOG) some time before you show up as a radar blip. This is due to the disparity in height above the water of a ship's AIS and radar vs. that of the smaller yacht. If you are on a too-close for comfort interception course with, say, a thousand-foot container ship, it's handy to know about that earlier than later and if giving way would be hazardous for you, you can contact the ship to request that they alter course slightly, which is best done leisurely on their end.

In short, while a decent AIS feed is better than squinting, it's no replacement for radar, because rocks aren't AIS targets, and AIS and GPS and a heading sensor to a modern radar turns it into a second, very capable plotter of sorts.

[Dockhead]

Originally Posted by alctel

As others have said, they are different tools that do different things.

I've found both invaluable, though if you don't sail at night or in fog much, AIS would probably be more useful than radar (although cheating when anchoring and using the radar to tell range from other boats is always nice )

As a single-hander I wouldn't be without either though (guard zones are the BEST, stopped me running into a dead whale(!))

Effective radar guard zones are awesome!! Such an extraordinarily valuable enhancement to watchkeeping offshore! My old Raytheon radar did not have good enough DSP to be capable of being tuned to a low level of false alarms, but the B&G 4G radar, which is mediocre on some fronts, is absolutely superb in this regard, with probably less than one false alarm per day in reasonable conditions, and almost never missing anything bigger than a crab pot. Absolutely awesome.


I use the guard zones as supplementary anchor alarm too.


I use the radar all the time for rangefinding in all kinds of situations, including in anchorages.


Fantastic tool.

Originally Posted by alctel

I dunno if radar training is needed but even reading the damn manual and playing with the settings on a calm open day is invaluable. And practice practice practice, the more I use the radar the more I realise just how damn useful it is)

Well, learning the manual from cover to cover is a great start, but you do actually need training (or serious self-study) to understand how to do a radar plot, and how to do radar navigation.

[River Cruiser]

I do a fair amount of boating at night on the Mississippi and Illinois rivers. I have Si-Tex 4kw open array and Comar AIS transponder. The AIS will not show the channel markers or the odd barge that may be tied up near the edge of the channel. They both have different value to anyone on the water, the radar are your eyes when you can barely see the bow. The AIS give name and navigation information on tows and tour boats long before you can see them. Together they compliment each other for safety.

[Dolphin460]

Unless money is a problem, both will make you safer. I sail the Med, sometime at night and sometimes in not the best weather, and I use both radar and AIS. Just my opinion.

[jen1722terry]

We live aboard in coastal Maine all summer. I can't imagine sailing up there without radar.

Some other posts recommended training in radar and we agree. It's a skill that can get rusty. What we do is practice the first day we dump in the spring. Even our 11 year-old radar with small display has a lot of information you can add to the screen using overlays and viewing the display takes practice.

AIS we haven't yet seen a real need for, as almost all the commercial traffic in mid-coast Maine are lobster boats and small tour boats, neither of which requires Class A AIS. We've spoken to some professional lobstermen and they do watch their radar while fishing, though they now rely on GPS to find their traps.

If were were sailing closer to Portland or Boston, we'd like to have class A AIS, but only as an addition to radar.

[P3sailor]

Radar does so much more than AIS and as others have stated not all vessels are equipped with AIS.

[Sailor647]

At first, I thought the title of the thread was a joke.

Yes, very much agree - different tools for different jobs.

If you can only afford one, go with radar. Unless you NEVER take your boat out at night or in the fog. And have excellent vision at dawn and dusk.

Only a few boats in Mexico have AIS. Those that do are usually lit properly at night anyway. Those that don't have AIS often don't have a single light on (pangas) or are lit up like the Taj Mahal (fish processing boats). Either way, it's impossible to tell their direction or speed of travel. Easy to track their movement using radar.

We have successfully used radar to dodge crab/shrimp pot buoys at night and even avoided a sleeping whale (or so we think) once.

Not having radar is like driving your car in the dark - WITHOUT HEADLIGHTS.

[alctel]

Originally Posted by Dockhead

Well, learning the manual from cover to cover is a great start, but you do actually need training (or serious self-study) to understand how to do a radar plot, and how to do radar navigation.

Fair point, I'm not sure I know how to do either of those.

[fgd3]

I have found AIS to be something of a fun toy. Updates just don't come fast enough for small boat handling. With big ships that are hard to turn AIS is valuable for collision avoidance but my experience with it on a small boat is the information isn't sufficiently up to date to be useful.


Fabbian

[CapnBazza]

Originally Posted by callistov42

My old Autohelm radar finally died. One of the electronics guys I was talking to suggested that if I installed AIS I really didn't need to replace the radar. The fact is that I almost never used my radar unless I was closing on a coast or looking for a reef. Another friend who’s boat is in New Zealand is really enthusiastic about the Vesper Marine “smart AIS”. I plan on putting a Raymarine MFD in the cockpit at the helm station (I already have one below at the nav station) that will repeat the chart and display the AIS information. Any comments about the need for both radar and AIS?

AIS will not show you my boat nor a few million others. Very few reefs, headlands and various other points of interest to navigators are AIS equipped either.

[David B]

Originally Posted by callistov42

My old Autohelm radar finally died. One of the electronics guys I was talking to suggested that if I installed AIS I really didn't need to replace the radar. The fact is that I almost never used my radar unless I was closing on a coast or looking for a reef. Another friend who’s boat is in New Zealand is really enthusiastic about the Vesper Marine “smart AIS”. I plan on putting a Raymarine MFD in the cockpit at the helm station (I already have one below at the nav station) that will repeat the chart and display the AIS information. Any comments about the need for both radar and AIS?

We were advised not to bother fitting RADAR. I realised as we were half way to North Africa from Italy at 03:00 with the moon having set, that we needed RADAR. Nice to see the boats out there with AIS, but were there any without?
We now have RADAR, and I use both at night - RADAR not so much, but it's there, and overlaid on the chart, is quite easy to use.

[Kenomac]

Radar Instead of AIS is more like it. Most boats and big heavy objects don’t transmit an ais signal.

[RaymondR]

If you opt for receive only AIS it's pretty cheap. I used a receive only unit with OpenCPN on my nav computer and found it to be very handy as it both identified the vessel and illustrated the course vector.

I have radar but it's at the nav station down below and as a single hander about the only thing I have found it to be any use for is having the guard zone set when I am hove-to and down below. I am in the process of moving it to the helm so that I can dodge unlit boats on moorings and confirm my plotter positions when entering or departing unlit anchorages.