Vesper Marine, new Class B AIS & antenna splitter


At first blush Vesper Marine’s just announced Class B AIS transponder seems similar to the Simrad AI50 and the Icom MT-500R, which is to say a transponder with a handy target plotting and info screen built in.  But I think the WatchMate 850 will be significantly different, because Vesper has been focused on AIS collision avoidance for years and has gotten quite good at it.  I finally got some hand’s on time with a WatchMateRX early this summer, and was even more impressed with the company when I met co-founder Jeff Robbins a few weeks ago.  I had not realized, for instance, that Vesper designed and built the AIS receiver that’s in the RX model, and they’re doing the same with the transponder as well as an interesting antenna splitter also announced…

Thus the AIS WatchMate 850 has a GPS patch antenna built right into its casing, so the installer won’t have to cable in a separate antenna if the unit has a sufficient sky view (though there will be an optional external antenna available if needed).  Thus, too, there’s an optional waterproof USB port to feed AIS target info to a boat’s PC, without need of a serial-to-USB converter, as well as a NMEA 0183 port for an MFD.  Though the 5-inch display head means the WatchMate can be used completely standalone if desired, and that includes sending a Class B distress SRM (Safety Related Message), saving familiar targets as “Buddies,” switching into silent (no transmit) mode, and decoding even currently obscure AIS messages like weather buoys, SARTS, and so forth.  And it uses only 3 watts from either a 12 or 24 volt supply, and it has an output for an external alarm, and built-in diagnostics.
   As complete and easy to install as the WatchMate 850 appears, Vesper has also tackled the issue of adding another VHF antenna with its own splitter design, described thusly:

Unlike splitters currently available on the market that introduce
insertion loss degrading the performance of both AIS and VHF signals,
Vesper’s innovative splitter increases AIS signal strength and range – a
truly valuable feature in response to the growing popularity of 2W
Class B AIS transponders. The SP160’s integrated amplifier increases
signal strength by 12dB. When used with the WatchMate 850 its already
industry-leading receiver sensitivity is further increased to a
remarkable -119dBm. The Vesper Marine splitter also offers visual
feedback with LED indicators for power, VHF and AIS TX signals, and a
unique warning light that triggers if there is a problem with the
antenna. Built in fail safes ensure VHF priority and maintain VHF signal
integrity even if power to the splitter is cut. When used with the
WatchMate 850 a visual indicator appears on the display whenever the VHF
radio is in-use to indicate that AIS traffic updates are delayed. The
SP160 uses standard VHF coaxial connections, provides an AM/FM
connection, works in both 12 and 24-volt environments, and is also the
only IPx7 waterproof AIS VHF splitter on the market.


But as smartly designed as Vesper’s hardware looks, I still think the company’s main claim to fame is the collision avoidance software built into the WatchMate 850 as well its 750 RX sibling and the original 670 display.  This software has improved over the years and perhaps the best way to see the latest version is via the videos posted on Vesper Marine’s home page.  The 850 press release, which should be online soon, calls it “the most intuitive and effective collision avoidance device ever built.”  I don’t know about that, but I appreciate the creative pride expressed, and it certainly is a noteworthy addition to the world of AIS.

Ben Ellison

Ben Ellison

Panbo editor, publisher & chief bottlewasher from 4/2005 until 8/2018, and now pleased to have Ben Stein as a very able publisher, webmaster, and editing colleague. Please don't regard him as an "expert"; he's getting quite old and thinks that "fadiddling fumble-putz" is a more accurate description.

10 Responses

  1. Ben Ellison Ben Ellison says:

    Incidentally, once it’s received FCC approval, the WatchMate 850 will retail for about $1,100, and the SP160 for $250.
    Also, I just realized that spec sheets for the 850 and splitter can now be downloaded at Vesper:

  2. steverow says:

    Hmmm, That screen although larger is not dissimilar from NASA’s Screen Stand alone AIS at $800 less, although unfortunately it has no PC connectivity as yet.

  3. Ben Ellison Ben Ellison says:

    Good grief, Steve, the NASA unit is not even a transponder. If it’s similar to anything in the Vesper line it’s the WatchMate RX, which costs a few hundred dollars more, and is worth every penny of the difference. Lack of a PC connection is only one of the NASA Radar’s weak points. How about the fact it can only receive one AIS channel at a time, which means it will only plot Class B targets every minute, at best? How about the funky faux radar plotting technique?

  4. norse says:

    The SP160 splitter PDF says VHF has priority over AIS.
    The Garmin 600 seems to take the other tack:
    The active splitter ensures that all VHF and AIS communications are sent and received with minimal signal loss or interruption, while ClearTrack ensures no interruption of the AIS traffic position transmission, even when the VHF radio is in use.
    (from the Garmin 600 press release)

  5. steverow says:

    OK Ben.. Sorry…how to make a fool of oneself to the world. It was late..that’s my excuse anyway.
    Yep I forgot it was a transponder, I was just struck by how similar the screens were…sort of murky monochrome LCD. I did have a NASA display once for a little while on the old boat, but couldnt see it very well, worked OK though. Why they dont put a serial or USB output on it though beats me..for a few extra quid. I would have thought that for over a thousand Dollars that the Vesper would have a better screen than that. As for the splitter, Ive never been a fan of these, either active amplified types like this, or passive diplexers, they invariably cause some sort of signal degradation or other unwanted effects. It’s just not good RF practice. Obviously the Vesper has a very sensitive RX amplifier in the splitter unit. I wonder how long it will stand up to 25W (or more) of crude RF up it. It’ll need a lot of dB’s Isolation.

  6. Richard C says:

    You mean it doesn’t output N2K, only NMEA 0183? That’s too bad, seems they got everything just right with this one exception. Did Jeff Robbins mention if this was ever considered? For such an outstanding product I can’t imagine they didn’t think of adding an N2K output during the 850’s development.

  7. Ben Ellison Ben Ellison says:

    Norse, I think that what the SP160 does is to give the VHF priority if power to the splitter is lost and hence it can no longer switch between AIS and VHF transmissions. I’m not 100% positive, but I think that all these splitters will switch from VHF transmission for the micro second it takes to send out an AIS message. What I don’t think any of them can do is to receive AIS messages while you’re transmitting on VHF, which is why Vesper puts up a warning icon on the WatchMate 850, but again I’m not 100% positive.
    Interestingly, the SP160 is rated for 12.5 watt AIS transmissions (and 25w VHF), which means you could use it with a Class A transponder, I guess.

  8. ToddR says:

    In my opinion, the screen of the WatchMate 850 affords a very crisp and clear view of information and targets. It is easy to read and understand in various lighting and at varying angles. Perfect for a stand-alone unit. I’m not sure what a “better” screen would be? And, it can easily interface for using the info on a more glorified platform.
    3 watts (.25 A @ 12VDC)! Great engineering – others are drawing 10X that to do the same thing. This is perfect for any offshore sailor.

  9. jeff says:

    Richard, yes we did consider N2K. But in the end we didn’t put it in for a few reasons. One is simply physical space for the connector (the unit is pretty compact and there are already four fairly large connectors on the back leaving no room for another). As a result, we felt a USB connection that can also power the unit was a higher priority. As with everything, there’s trade-off’s…
    Regarding the splitter: Yes, it always gives priority to the VHF even if the power goes off. This is important because we’ve found there are other splitters out there that provide no isolation when their power is off and therefore they can inadvertently damage AIS receivers.
    With respect to the screen… unfortunately the screen photos always look fuzzy when reduced for web. I think the actual screen is very crisp and it’s even better in direct sunlight.

  10. Ben Ellison Ben Ellison says:

    Vesper Marine’s AIS WatchMate 850 Class B just got FCC certification and will retail here in the States for $1,100.

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