AIS A or B?

[OffshoreDreamer]

I'm writting my Christmas letter to Santa and trying to decide whether to ask for the A (receive only) or B (transmit/ receive) version of AIS.
I do coastal sailing out of San Francisco Bay where there is lots of commercial traffic and it is often foggy crossing the bar and along the coast beyond.
Does anyone have experience to share on the subject?

[Tempest]

Given a Choice.... it's better to see AND be seen...IMHO

[speciald]

I have a Reciver and thought about getting the Raymarine reciever. It uses an antenna splitter so a second VHF antenna is not needed. The FCC requires a separate GPS reciever for some unknown reason. After concideration, I decided to wait until the prices drop.

[BarryL]

Hello,

I can't really offer you and advice but I do want to make a clarification. There are two AIS classes, A and B. Both of them are transmitters. Class A is for vessels that are required to broadcast AIS data (commercial vessels, etc.). Class B is for vessels that are not required to broadcast AIS but wish to do so.

Types of Automatic Identification Systems - USCG Navigation Center

There are many ways to receive AIS data. The simplest is probably the new Standard Horizon GX2100 AIS VHF radio. I am considering buying one. You can learn more about it here:

Welcome to StandardHorizon.com

Good luck,
Barry

[MJBrown]

Struggled with the same question and finally decided to go with a Class A ICOM MXA-5000 reciever. Bought it from Defender as a boat show deal for $412. Several considerations played in the decision. 1. Can't imagine every pleasure boat broadcasting an AIS signal. It would certainly clutter the chart plotter thats for sure. 2. As long as I know where and who the big boys are I'll make the first move to get out of thier way. 3. The price differential was too large to justify the Class B types. 4. Installation seemed to be the easiest. This proved to be true with the hardest part involving running the data cable from the AIS unit to the plotter. Most of the issues were due to the boat not the unit. As for performance I'll have to wait until spring to determine but sitting in my winter slip it picked up 3-4 ships a couple of miles down river. Not sure if the VHF signal will be degraded since the AIS shares the same antenna.

[billyruffn]

I have a transmit/receive unit and love it....well, most of the time. To summarize my experience to date....

To see others is very nice: really helpful to know who's there and where they're heading, CPA, etc., especially in reduced visibility and offshore at night. (But remember, not everyone has AIS -- only a few well heeled yachties and the big boats).

To be seen: a real bonus for a small boat and the primary reason I bought it.

An issue: in tight spaces (like SF Bay) with lots of traffic you'll go nuts turning off the alarm every time someone gets within a 1/4 mile. It's especially bad when you're coming into a tight space to anchor or pick up a mooring and you're trying to concentrate on driving the boat and the system keeps telling you "Dangerous Targets" are everywhere.

Question: What's next in line for spending a BOAT unit? Is AIS your top priority upgrade?

[negrini]

I second MJBrown and have same unity mounted for a couple of months now. The easy installation was determinant to not pick a trasmitting unity. ICON has a terrific log on radio appliances, and MXA-5000 is not different; well built, simple to use and (we hope) a long service. As we experienced, VHF degradation is very little and I could measure only using a RF meter, not noticeable hearing or squelching so far. This, plus our RADAR on an E120 plotter, makes our first line of deffense. Now we simply call out the target vessel and make sure they know we're here. For the first time, big freigthers respond promptly to our call and provide usefull information on weather and intention, so politely we feel part of the commercial traffic .....

[MJBrown]

Negrini, happy to hear you have had good experience with the ICOM AIS. Also good to hear the VHF has not lost any power. Sounds like I made the right decision. You mentioned your radar. Which unit do you have? I'm planning on adding radar this spring and not sure if I want the RD418D or
RD418HD model. The last having some new features such as the ability to view both short and long targets on a split screen.
Mike