AIS transponder

bluestreak

Well-known member
Joined
Jun 25, 2010
Messages
232
Fluid Motion Model
C-28
Hull Identification Number
fmlt2733c616
Vessel Name
Blue (2016) Call sign WDL3080
MMSI Number
367752840
Wondering what the knowledgeable PNW boaters think about replacing the AIS receiver with a transponder?
You know what other vessels are out there but do they know you are out there?
I know it requires an additional VHF antenna in addition to a newer unit.
 
I swapped out the Garmin AIS 300 with a Garmin AIS 800. The new unit is happy with its internal antenna, and fits where the old unit was (R31S). Plug and play, no drama.
 
I recently installed a Garmin AIS 800 in my 2018 R29s. I also installed an external GPS antenna because I heard that the internal antenna was the weak link in that unit. I mounted the black box below the helm, next to the water heater and installed the antenna just forward of the helm under the deck (out of sight).
Then install was very straightforward, and plug and play. It has worked well.

IM me if you want more detail.

Thanks.

Rocky
 
That is good news. Better than I hoped.
Thanks
 
We upgraded to a Garmin AIS 600 when our boat was built.

We wanted to present another electronic signature of our presence, rather than just radar, or line of sight. We are often confronted with fog here in the northwest, where transmitting an AIS signal is an added layer of safety.
 
I have read of several reports of the AIS800 internal antenna not being good enough. Some of it depends on where in the boat it is located. All who have installed an external antenna have reported good results with more accurate position reporting.
 
As I understand it, the unit in only transmitting with 5 watts of power so the higher above the water the better; cabin top is better than deck level.
 
We put a Garmin 800 in our C30, mounted behind the helm. The GPS signal using built-in antenna was weak and often failed until I added the external antenna (coiled up next to it behind the helm -- thought I'd try that before drilling any holes). With the added GPS antenna, it has been rock solid for months. I've seen no reason to move that antenna out of the helm cabinet but it would be an option if ever needed.

As for transmit, it uses a built-in splitter with the existing VHF antenna so that will be as strong as your radio. That does mean that you need to install the unit somewhere with access to that antenna/radio connection, and to the NMEA backbone (thus the behind-helm location is perfect).

A nice bonus is that you can track your boat (and check on the AIS status) with apps like Marine Traffic. Overall I'm very happy with it and would do it again exactly as is.
 
SJI Sailor,
What did you use for the extra antenna behind the helm?
If it works well there, one less hole on the cabin top.
Bill
 
I had the factory install AIS800 in their factory for my new 2019 R29 CB NW Edition. At first it worked and then after a week or so after I did an update to all the Garmin gear it started to flip off and on and then stopped OFF altogether. RT came out and redid the software and mounted an external antenna close to the AIS800 box at end of cave behind a panel. The AIS now works perfectly in all conditions and get at least 8 satellite sightings most of the time.

It is an extra layer of safety for sure. I believe it also allows your boat tracks to be picked up and displayed on one or more of the marine traffic web sites such ashttp://marinetraffic.com/ and http://vesselfinder.com/
 
For the external GPS antenna, I used the Garmin GA 38 ($70). It comes with several mounting options and a long cable. I just coiled the cable and placed it resting upside down in an available space in the behind-helm cabinet (with some velcro added to stick its top to the bottom of the cabinet area, to hold it in place just in case).

I thought that might be temporary but it has worked perfectly for three months so far -- no loss of GPS at all, and very tight tracking on the services such as Baz mentions.
 
Thank you for the info on the antenna.
Not much space in that helm box on the R27.
 
If it helps, the antenna has a 32 foot cable, and a bunch of mounting options. So I'd try to find anywhere else on the boat you could run the cable (quarterberth maybe?) As long as it's not under metal or in the bilge, I expect almost anywhere else would be as good as the helm cabinet (maybe even better, since away from the electronics)
 
I noticed the cable length.
I look around and see what will work best.
Thanks
 
Looks like most everything has been said already, but nevertheless I though I would relay my experience. I received a new 29S in July with AIS800. It took about 3 months to get it to work. Resolution required installing an external GPS receiver and improving the VHF connection to the AIS unit. Garmin told me that the internal GPS receiver would have been fine if the AIS unit had been installed horizontally on a horizontal surface. However it could not work well as installed vertically in front of the helm. It was not necessary to install the additional GPS receiver externally (i.e., on the mast). Regarding the VHF cable, it was installed with a crimped-type fitting which the AIS did not like (too much resistance). This was resolved with a soldered fitting. Note, AIS broadcasting uses the VHF antenna.
 
I should add here, that I believe RT has now abandoned using the Garmin's AIS800 that quite likely was attributed to the issues RT owners had had (including me) and now use a different brand.

In my case, the AIS800 box is installed vertically nearby (within inches) and close to the NEMA backbone and Auto Pilot compass below the engine's Throttle base. It can be access fairly easily via the pull out panel at the end of the cave area.

In my case, I may have disturbed things when I upgraded all my Garmin gear with the latest software releases. This software installation for me was not without issues and posted this elsewhere in this forum. The AIS800 worked well when at the factory parking area, but became problematic after my software upgrading activity.

RT was kind enough to come to my boat and redid the AIS800 software install and attached an external GPS antenna that was the same one used to install high up on the mast by others. It was installed in a vertical position just behind the pull out panel at the end of the cave rather than externally on top of the cabin or top on the mast. Obviously it was easier to install where I've said rather than externally which would have required running the cable through the cabin and to the outside.

For me now, having this AIS800 setup in use for several months I can say it's working without issues, and I'm quite happy with it's performance.
 
I'll have to check that aspect out when I replace the 300.
That won't be till next spring.
Thanks
 
On Toucan, we replaced the Garmin 300 AIS with a Vesper Watchmate XB-8000 transponder. Very easy install with the GPS antenna in the cubbyhole above the helm and the VHF antenna cable passing through the the cabin wall just under the front eyebrow and up through the eyebrow. AIS receiver info is still pitifully displayed on the Garmin MFD as before with the Garmin 300 AIS. The AIS info is also blue-toothed to our iPhone using the Watchmate app. The info displayed on the iPhone is prioritized by risk, very useful and permits the MFD to remain on the chart view.

We also installed a toggle switch to turn off the transmit function when not needed. We detest receiving AIS signals from boats moored in marinas. Anchored boats dancing around in the wind or currents can set off impending collision alarms when you are anchored or moored in a marina and moored boats can do the same when you are anchored. Silent mode is also useful if you are going a bit fast in a No Wake zone.

We bought our unit from Milltech in Port Orchard, WA, and received excellent service and coaching on the install. We recommend the unit and the vendor.

Barry and Lynne Thompson
 
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