Vesper Cortex Review

I’ve been excited about the possibilities for the Vesper Cortex ever since first hearing about it. It just makes so much sense to combine VHF and AIS in one unit.

(In a nod to this, other vendors are now scrambling to catch up.)

So this past weekend I updated from the Vesper XB-8000 to Cortex. Installation took about a day and was straightforward. Compared to the XB-8000, its splitter, and miscellaneous associated hardware, the Cortex saved quite a bit of real estate in the installation area.

I’ve only experienced Cortex at the slip so far, and will update this article as I learn more. Here are my initial impressions.

(Answers to questions, as obtained from Vesper Marine support, appear in bold.)


  • As a software engineer I can appreciate the tremendous amount of effort represented by the hub, handset, and mobile app software.
  • I’m really excited about the built-in heading sensor. I won’t be able to say more until it calibrates. I’m hoping that it will output the heading PGN on the NMEA 2000 network.
  • The manual mentions a built-in barometer?
  • There’s huge potential for this little unit. So far I’m impressed!


  • One of my favorite features of the XB-8000 is that it can alarm (collision, anchor watch) when no display is connected.
    • Does the Cortex retain this feature? Yes
    • Is the external speaker needed for this functionality? Yes
    • Is it possible to have just alarms on the speaker so you’re not hearing VHF chatter all night? Yes, VHF can be muted
    • Is there a way to connect a loud piezo buzzer if desired? Not at present
    • Is it possible to silence AIS/collision alarms while at anchor (so that only anchor alarms will be announced)? Yes
  • The manual suggests that use of any GPS antenna besides the one supplied may damage the hub. Is it possible to re-use the Vesper GPS antenna which came with the XB-8000? Yes
  • Is there a way to disable automatic checks for updates? I only want to check for and install updates when I explicitly initiate the process. I never want to be prompted for an update with a pop-up, which invariably comes at an inopportune time. Nothing should ever interfere with the system’s primary function as a safety device. Not at present
  • Is there a way to turn off the 3G network access? I’m almost certain I’ll never use this functionality, and I don’t need the system to “phone home” and upload who knows what data. Also reduces the security surface area. Not at present
  • Is it possible to change the WiFi SSID? For security reasons I’d rather not broadcast that there’s a Cortex aboard. Not at present
  • Is there a way to tune the AIS collision alarm settings like on the XB-8000? The XB-8000 had settings groups such as “Harbor” and “Offshore,” which could have their alarm criteria fine tuned. The Cortex settings groups “At the helm,” “On watch,” and “Autopilot engaged” don’t make sense to me (what do those mean exactly?), and I don’t see a way to view or configure the alarm criteria for those groups. Update: there is now


  • I’d like to be able to tune to the weather channels. Set the handset to the “US” region (default is New Zealand)
  • I wish there was better tactile feedback from the handset’s push-to-talk button. It is hard to tell by feel if it is depressed or not.
  • The handset is quite slow to boot. I’m not sure there’s much that can be done about this, but faster booting would be fantastic.
  • I’d like an adapter so a tethered handset can plug into a standard 12 V socket.
  • [iOS app] When the WiFi connection to the hub is lost, a modal screen should not be presented which prevents use of the UI. It’s ok to visually indicate the WiFi connection loss and/or otherwise indicate the increasing staleness of data; however, the UI should still be navigable when the WiFi connection is lost. (Perhaps I want to scroll the plotter display to see the last known position of a vessel, for example.) This is most noticeable when bringing the app to the foreground.
  • [iOS app] Target COG and SOG are always displayed together; that is, either both present or neither. It’s not clear if this is because a message containing these values was never received, or if one was received at some point but considered too stale to display. Since the target display indicates the “last updated” time, I believe it is preferable to display the last known COG and SOG here even if stale.
  • [iOS app] I’d like for landscape orientation to be supported on the iPad.
  • [Hub] WPA2-TKIP WiFi is vulnerable to numerous known attacks. Please implement WPA2-AES instead and remove TKIP, especially considering Cortex’s status as a safety device (and perhaps some customers’ views of it as a security device).
  • [iOS app] In the AIS directory view, a vessel described by its MMSI is not updated with its name once the name becomes known. Exiting and re-entering the AIS directory will update the list with the vessel’s name. The entry in the list should update in place from MMSI to vessel name as soon as the name becomes known.

Pie in the Sky

  • Presumably the Cortex is based on a software defined radio, listening to a broad spectrum and capable of receiving transmissions on multiple channels simultaneously. You could automatically retain recordings of the last hour (or whatever) of transmissions on all received channels when the signal is above the squelch level. And as a user, I could
    • Hear what conversations I missed on channel 13 over the past hour
    • Quickly replay an announcement that just came in
    • Save an important clip for playback beyond the usual recall limit

Update: this has been implemented now

Bugs & Issues

  • Once, the handset switched itself to high power mode. Although, looking in the menu, high power was not enabled. Enabling then disabling high power returned the handset to low power mode.
  • The handset showed a depth sensor reading of 9’ 12”, which does not make sense. I suggest that depth is displayed in decimal feet rather than feet and inches. Update: this has been fixed
  • The WiFi connection between the hub and the tethered handset at the helm 10 feet away is sometimes unreliable despite not being very far. This is using the external antenna (and it is enabled). I haven’t yet tried the internal antenna.
  • The gasket fell out of the weather cover for the bulkhead tether connector in a matter of hours. It appears torn, too.
  • The plastic housing of the handset is slightly loose and wiggly. Ideally it’d have better tolerances or a more secure screw-down. This is intentional – the cover is cosmetic and protects the speaker, and does not affect water tightness
  • The handset installation manual shows the weather cover for the bulkhead tether connector hanging in the down direction from the connector. However, in the unit I received, due to the way the cover is “keyed” to sit on the notched connector, it either had to be twisted 180 degrees or installed hanging up. I chose to install hanging up, although this means the “Vesper” name on the cover is upside-down.


Although I’ve highlighted a few issues experienced, they’re relatively minor, and there’s surprisingly few considering this is a new product of ambitious scope.

Overall Cortex is a worthwhile addition, a huge boon for safety, and I’m excited for present and future possibilities.

Update 3 Jan 2021: Measured the Vesper Cortex current draw. Note my ammeter has a resolution of 0.1 A, so a difference of 0.1 A between two readings could actually be less than 100 mA.

  • Cortex Hub: 0.7 A @ 13.0 V
  • Handset, off: 0.1 A @ 13.0 V (yes, it appears just plugging in the handset consumes power even though it’s “off”)
  • Handset, standby: 0.2 A @ 13.0 V
  • Handset, on: 0.3 A @ 13.0 V
Side-by-side comparison of Cortex (left) and XB-8000 (right).
Handset switched itself to high power even though the option was not selected.
Handset displays some odd depths.
Rubber gasket torn and fell off within hours.

2 replies on “Vesper Cortex Review”

Hi Chuck,

I came across your review and here a few things I can add …

> Is there a way to disable automatic checks for updates?
The updates are contained in the iOS Android apps, which is why they are so big. So if you don’t update the iOS / Android app, there is no software update to be applied. Also, updates are sent from the app to the hub and from there to the handsets, but you can still not apply the update. Not sure why Vesper did not come back with that info.

> Presumably the Cortex is based on a software defined radio
Yes, 8 channel capable. See where Ben states “Vesper says they plan to implement additional scanning modes in the future and will use another of the 8 available channels for scanning.”

As you say there are some rough edges to the software and functionality here and there, I keep searching for features (which I eventually find …) so it is not yet as easy to use as I think it can be.

My pet gripe is that the button backlighting on my fixed handset H1 is much less clear than on my H1P.

Hello Kees! Thank you for your additions.

1. I recently went through the update process, and understand it better now. I was initially concerned they might download updates over the 2G interface and update “behind my back” as seems to be the tendency these days. Glad to know I have the ability to control when updates are applied. I wouldn’t want a buggy auto-update right before going offshore!

2. Ah interesting, thanks for the link! It sounds as if each of the 8 channels can be independently tuned to any frequency in the VHF spectrum. Perhaps their SDR sees the entire range, but they’re limited to 8 simultaneous demodulations.

Yeah it has its rough edges, but it’s definitely headed in the right direction. I really appreciated the antenna pass-through so I can use my trusty Icom as a backup.

I haven’t seen the H1P yet. How’s the battery life?

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