Garmin GPSMap 640, hands-on #1


One gizmo that’s definitely coming along on the Gizmo delivery is this Garmin 640 beta unit.  In nüvi mode it can navigate the highways down to Connecticut, as it’s done well twice already, and I can then reboot it into marine mode for the voyage home, with XM audio and weather available all the while.  The marine satellite weather presentation seems particularly good, as you can see somewhat if you click on the screen above; it’s set up so that the Nexrad radar and cloud cover are animated and a finger tap leads to a choice of local forecasts, buoy data, and more, depending where you tap.  But finding a good place for this 18 ounce “portable” on your dash or at your helm may not be easy…

I don’t really understand why Garmin equipped the 640 with a 9 hour lithium-ion battery (it’s hard to picture pulling that 5.5″ screen out of a coat pocket), but I can tell you that the unit has enough mass to sometimes overcome the car mount seen above, despite its large, bendable, and sticky rubber base.  And you know it when this baby lands in your lap!  Now that same base will work fine at either of Gizmo’s helms, as would the marine swivel mount (below) that comes with the GPSMap 640 package.  I’m also pretty confident that the GXM40 Smart Antenna will bring in XM OK through the boat’s main cabin windows, but wonder where a sailor would mount it if he or she wanted to install the 640 on his or her wheel pedestal.  The antenna does come with a USB extension cable, and a choice of fixed or magnetic mounting plates, but will still be awkward at some helms. I also wonder if the the 640’s IPX7 waterproof rating — 30 minutes at 1 meter depth — still applies if the rubber USB port protector cap is open?
   Note that the marine mount’s power cable includes two NMEA 0183 ports (N2K would have been sweet, but these will work for AIS, wind, depth, etc.).  It also has stereo output wires, and both bases accommodate stereo mini jacks.  So you can use a 640 in many ways, including maximization of an XM subscription (now less expensive, but still not trivial).  I do wish the 640 showed more weather detail in street nav mode, but then again know that Garmin has pleased many customers by keeping things simple.  The marine nav mode looks good, except perhaps for its inability to do split windows, but I’ll save that discussion until I’ve really used it on the water.  I will note, though, that when Garmin says “modes” it’s not kidding.  The 640 (and probably its GPSMap 620 cousin) are truly dual boot devices.  It’s not a significant hassle, but the street and marine modes acquire GPS fixes separately, store weather data separately, and even get updated separately.


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.

11 Responses

  1. SanderO says:

    Where from/ when is the delivery? Do you need company or a hand? Are you going to “document” the event?
    As you may recall I have written about my Garmin PDA iQue which does marine and streets, but is rather basic compared to the 640. But mine fits in a shirt pocket, no sweat. The battery sucks. But up close, these little guys are great.

  2. Ed Herlihy says:

    Hi Ben,
    Congratulations on the new Panbo testing lab!!
    I am pretty sure that this is the touchscreen model that replaces the GPSmap 478/378.
    I have the 478, and LOVE that it includes a battery for several reasons. First, when renting a car or a boat, I have found that the power adapter/cigarette lighter adapter may not always fit properly, and will pop out. Because the unit is also battery operated, I acknowledge that power has been disconnected (in my case by pressing a button), and continue on my way.
    One frustration with the unit is, despite the fact that it includes all the US Coastal charts and Street Navigator, the charts eventually become out of date.
    Garmin does offer a program whereby you can update an INDIVIDUAL chart, by purchasing an individual Bluechart card, update that chart, and send the card back to Garmin. The cost per region is ~$90. If you wished to update all the charts, it would more than exceed the cost of a new unit.
    I wish that there was a service that would allow you to update charts through the USB connector. Alternatively, I wish that there was an option to update all the charts to the most current version available.
    I hope that with all the new projects that you will have with the new Gizmo, that you have time to keep up the great work at Panbo!

  3. Dan says:

    I have been waiting for this forever, but after finding out the Nexrad radar does not work in Automotive mode, I will have to just hold on to my 478.

  4. John says:

    That there is funny.

  5. Rich Owings says:

    Can you verify that the weather features are not available in automotive mode?

  6. Ben Ellison Ben Ellison says:

    Rich, The only weather I’ve found so far in street mode is city specific conditions/forecasts and general frontal forecasts. No NexRad, no a lot of stuff. Plus, if you switch over to marine mode for the excellent data presentation there, you have to wait for the unit to collect it because you rebooted.
    But bear in mind that what I’m trying is a beta unit. And also that Garmin has a pretty good track record for improving software after a product’s release. The GMI10 is a good example; it started as great hardware with some serious software annoyances, but during its first year or so was fixed (spectacularly, I think).
    Incidentally, people comparing the 640 to the 478 family should heft it. It feels a lot bigger to me. Heck of a screen, though.

  7. bwp says:

    Ben …
    Ive been using my 376c going on five years and it’s withstood my trail by fire for sure. My unit has been thru many an offshore storm (GXM30 antenna included) and never missed a beat. The mini usb connector has never had any issues in regards to water intrustion. I move it from my boat to truck frequently without issue. XM connectivity is solid as a dollar from the dash of my truck.
    I have a 640 in hand and will shoot some on water videos in the near future. There are software additions/modifications in the works.
    Auto mode …. short video {click below}

  8. Ben Ellison Ben Ellison says:

    I can’t find the video, BlueWaterPirate…which album?

  9. Garmin Fan says:

    Garmin offers a single update card for the 478 that will update all US charts. They just announced a new g2 mapping update available in June that would be worth waiting for. Here is the link if your subscriber wants more info.

  10. Ben Ellison Ben Ellison says:

    Has anyone else had foggy screen problems with a Garmin 640? I have a friend who just got his second free replacement from Garmin, and apparently its screen was fogged right out of the box. Which makes three in a row. I have not heard that this is a common problem with the design, but can my friend be that unlucky????

  11. keith says:

    I have had a Garmin 640 for over a year. It works great in the truck or the boat. I’ve had no issue with the screen getting foggy. Either I’m lucky or your friend is really unlucky.

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