Good AIS receiver?

I'm looking for a good receive only AIS receiver. Recommendations? It's going to feed into my navigation computer.

The Raymarine AIS 350 is receive only and has a USB output to transfer signals to a computer for overlay on a digital chart. It comes with a CD containing SW for the connection. It works fine for me with Open Captain.

I have the Simrad AI50 Transponder. Installed it last year and am extremely happy with it. While it will interface with other equipment, my Furuno Navnets are too old to work with it. I use a separate Shakespeare antenna on a 12' mast extension as the signal is line of sight, VHF. It picks up all signals by 24 miles and sees many big ships as far as 48 miles. The transmit section can be turned off if you wish to run drugs undetected. :lol: I think being able to transmit is a valuable option if you are broken down and drifting or traveling in shipping lanes. Mine is on my charter boat primarily to tell ships I am anchored and conducting underwater operations. This has made a huge difference as ships now see me more than an hour in advance and miss me by more than a mile instead of the usual last minute course alteration and a 1/4 mile nail biter.

Ted

I have had excellent results from a Digital Yacht AIS200Pro unit, direct USB attachment to a personal computer. Purchased for $264 from CascadeGPS at Digital Yacht AIS200PRO AIS Receiver - Cascade GPS

I just installed a Garmin AIS 600. Great unit. Easy install and no dedicated VHF connection needed. Installs inline with your current antenna. It's nice knowing the big guys can see ya and fun tracking your movements online.

Ship Finder | Live Marine Traffic | AIS Ship Tracker and Tracking

Standard Horison has a couple VHF transcievers with built in AIS receivers. They will display AIS information on the receiver itself and/or most common chart plotters.

I have had good luck with Comar AIS receivers from Milltech Marine.

I also have used a Comar AIS receiver (Milltech) for the past 3 years. Works great. No problems. I have a dedicated mast head whip antenna and display on a 12 inch Standard Horizon chartplotter. Right or wrong, I chose to go with just the receiver because of concerns about antenna placement with the transponder unit. My understanding (limited!!) is that there needs to be good spatial separation between an AIS transmitter antenna and other VHF receiver antennas, otherwise the outgoing AIS signal may damage / interfere with the VHF.

I see a lot of them come with VHF antenna splitters now. Is that tech OK or is it really important to have a separate antenna. I can replace my defunct LORAN antenna with another VHF if necessary.

I read a post by someone on another forum that said they measured the output with and without the AIS being in the circuit. With the AIS in the circuit the output dropped to 10 watts and without it was measured at 10 watts.
If it were me I would use a dedicated antenna. But that is just me.

I think the dedicated antenna is the better option. Not clear to me whether the concern about antenna position for transponders relative to other receiving antennae is valid or not. I just played safer.
Chris

A separate dedicated antenna is required for AIS transmit/receive systems.

However, for receive only, you can share your VHF antenna by using a splitter. The splitter disconnects the antenna from the AIS to protect it when the VHF is transmitting.

Advantages of a splitter:

No second antenna is needed, wiring is greatly simplified and antenna location issues are avoided.
Some splitters include an amp to increase signal reception range.
Some splitters include a USB output for a laptop to receive AIS signals for input to a navigation SW.
Some splitters include an AM/FM output saving installation of another antenna.

Disadvantages of a splitter:

Momentary loss of AIS update signals while transmitting on the VHF.
Possible minor loss of VHF reception distance (which can be offset by number 3 above).

Make sure the splitter is designed to fail in the VHF transmit mode. Also, make sure the splitter is always on when the VHF is on by connecting it's power to the same breaker as the VHF.

I selected the Comar ASR 100 VHF/AIS Antenna Splitter which has all the features above and cost much less than a second antenna.

Here you can see the Raymarine 350 and Comar ASR 110 mounted in the ceiling above the navigation console. The back of the ICOM is on the right. The antenna cable input is moved to the splitter and the splitter output cable goes to the ICOM.

Papa Charlie said:

With the AIS in the circuit the output dropped to 10 watts and without it was measured at 10 watts.

Click to expand...

Hmm....

I just installed an AIS 600 from Garmin. It's a transmit/receive unit and is a great gadget to have aboard. I didn't notice any appreciable degradation when I used the AIS inline with the VHF at all, but a 2nd $100 VHF antenna gets me a spare if I ever need it too.

Originally Posted by Papa Charlie
With the AIS in the circuit the output dropped to 10 watts and without it was measured at 10 watts.

Click to expand...

I need to proof my posts a little better.

My post should have read 10 watts with and 20 watts without.

The thread I read was for a Garmin send and receive unit.

Papa Charlie said:

My post should have read 10 watts with and 20 watts without.

Click to expand...

Yeah... I saw that one as well and knew you had just made a typo. I doubt it was as bad as that or he likely would have gotten very performance from the AIS side of the transceiver as well. I have two antennas on mine and it was mainly just an exercise to validate my old antenna.

AIS only transmitting at 2W was a bit of a surprise and when the local volunteer AIS contributor for the Everett area wasn't showing me on Shipfinder.com I was wondering if my antenna was getting a bit long in the tooth.

It is nice knowing the big guys know what you're up to. I crossed the shipping channel with the Hyundai Shanghai bearing down on me at 23 knots and the AIS helped me realize that passing ahead of him wouldn't have worked.

I'm sure someone on his bridge team was watching me make that decision on AIS as well.

While using some items for dual purposes may be fine, when it comes to safety I, personally would opt for dedicated systems. But that is just me. Plus as you indicated that provides you with a back up antenna should anything happen to one.

Yeah I get that. The Garmin doesn't use a simple splitter though like some of the receive only units have. It's an actual solid state switch which is part of why I doubt his results a bit. But... I have the antenna now and the redundancy is nice.

My longer range plans are to mount a second VHF and use the Garmin AIS switched input for it. I have a single VHF now (with dual stations) and would like to have the redundancy of the second system.