Maretron SMS100, advanced NMEA 2000 monitoring via cell texts

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.

16 Responses

  1. Ben Ellison Ben Ellison says:

    PS for the sake of context: Note that the Empirebus N2K digital switching system now associated with Raymarine includes GSM texting ( ) and that Garmin could probably add N2K monitoring easily to its GDL40 cellular weather transciever ( ) which costs a fraction of the SMS100.

  2. Karl in Northern NY says:

    I must be missing something here. Does this “thing” require its own cellular account? It would seem so since it apparently has a SIM card installed. Can it “share” an existing cell phone account, since all it seems to do is SMS, perhaps a half-second data burst over the network.
    Can the device (and/or account) also be used for remote monitoring of other things, such as an network camera with IP address, just as an example?
    All these things that require monthly subscriptions add-up fast and adding another cell account is not high on my list of priorities.
    Are there SMS-only cell accounts available cheaply? I believe the Kindle reader, for example, has essentially free 3G imbedded service with no subscription charges. Of course, those generate income whereas Maretron only profits once, from the sale of the device itself.
    Do they offer a WiFi alternative so a SIM card and account would not be essential, for those of us who only need to get alerts while docked where there’s WiFi available (at dock or on boat WiFi network). Also, how does it send an alert if you are out of cell service range? A stored alert for high bilge water is not useful two days later.
    It seems like the redundancy of WiFi or Bluetooth (or even satellite) would be mandatory for a device upon which you depend on for critical alerts, otherwise it’s just a toy for inshore use only. Hell, I’m just a lake boater, and about 85% of where I boat has no cell service at all.

  3. That is an amazingly expensive hammer ($700) for this simple nail. You can send a text via email quite simply. Why have this piece of hardware and a separate SIM? Alternatively, this looks like something that a small app on your phone and Chetco’s much less expensive n2k interface could do quite well.

  4. Ben Ellison Ben Ellison says:

    Good questions, Karl. Cellular boat monitoring products typically have their own SIM card, phone #, and account. Siren Marine, for instance, provides service for $180 a year with unlimited messages, or $18/month.
    Maretron recommends AT&T service but says the SMS100 will work with many cards. They are sending me a unit to test so I bought an empty AT&T GoPhone prepaid card for a few dollars on Amazon, because I have no local AT&T store and they don’t seem willing to sell just the card online. But hopefully I’ll be able to activate it online and can either go with no prepaid plan and pay 20 cents per message or buy a bundle of 200 for $5 a month. Info here:
    The Maretron SMS and other GSM monitoring products like Siren Marine and Cobra’s C-Pod Security system work with text only. Maretron does in fact offer a higher-end system with off boat video, but it’s a lot more complicated and expensive.
    I ran Siren Marine 24/7 from South Carolina to Maine and while I definitely cruised beyond cellular sometimes, I don’t think I ever anchored or moored and went ashore anywhere that I couldn’t check the boat via a text message. Had it dragged or been stolen, I’m pretty sure that the Siren system would have let me know and would have tracked the boat.
    But that situation will likely change when I cruise further east in Maine and even my harbor is tough on GSM messaging even though AT&T voice/email works fine here. I plan to run both Maretron and Siren and will report on the results.

  5. Ben Ellison Ben Ellison says:

    Hi Steve, I certainly won’t argue that $700 for a waterproof NMEA 2000 cell modem isn’t high but I think you’re getting a whole lot of unique development work in the package. I don’t believe that any other manufacturer has worked out the breadth of sensors, the depth of device management/calibration, and the alerting sophistication that Maretron has. In fact, there’s an argument that DSM250/150 on board alerting with SMS100 off boat extension delivers a lot of the value of N2KView at a much lower cost.
    I’ll add that BEP C-Zone also seems to have advanced alerting plus great access to N2K sensors, though no easy way to get it off the boat (yet). And no doubt there will be some interesting monitoring apps as turning N2K into WiFi gets easier (as with Chetco SeaSmart). But I don’t get how leaving a phone or tablet on the boat is an easier solution than a $5-15/month prepaid SIM card, unless it’s just while you go into dinner on a cruise. The Siren Marine has actually been running on Gizmo since October and it gives me significant peace-of-mind about my favorite possession.

  6. HenryD says:

    Thank you for the posting.
    I looked hard at Siren Marine at the Annapolis Boat show but their product would not interface with NMEA2000 sensors.
    The N2KView Alerts module is just too expensive for me. Most boats that have Maretron and N2KView probably have a router/wifi network which would be the easiest way to send SMS messages.
    Putting in a $700 module + monthly cost will not fit in my budget. If I am going to do that I would use the Maretron cloud services.
    What I do now is simply run LogMeIn on my helm PC and then I can connect via my cell phone, iPad, laptop and Surface. This lets me see my N2KView, my video cameras, RosePoint and all of my manuals.
    I recently added a Synology server which provides a onboard mail server, network attached storage and much more.

  7. Ben Ellison Ben Ellison says:

    Thanks, Henry, but I’m confused. No one has to buy the N2KView Alerts Module to use the alerting features now built into the DSM displays illustrated above, which can also be set up using the free N2KAnalyzer program on a PC. In fact, it looks to me as if Maretron has brought some of N2KView’s on/off board monitoring sophistication down to less complicated, lower cost and lower-power display and communications devices.

  8. HenryD says:

    The DSM displays or the N2K Analyzer require something to send the SMS messages and if you are using the SMS100, after the cost of the unit, you then need a separate SIM card/account with a repeating monthly service. Is there a way to use the DSM or N2K Analyzer to send SMS without the SMS100?
    The other option is the use N2KView Alerts module since I already have N2KView running on a PC.
    It’s great that Maretron has added this ability on the DSM displays, but I do not have any aboard and really do not want any. I would rather keep the displays on the PCs where they can be used for other things too. It is really helpful that Rosepoint displays alot of the N2K values so I do not have to keep N2KView up all of the time.
    The boat already has it’s own ethernet network, router and broadband/aircard connection. Do I want another monthly cost for the SMS100 sim card? Not when I can use GoToMyPC or LogMeIn and connect from my phone or iPad to see my N2KView and other solutions.

  9. Mike says:

    I see on Siren Marine’s website that the system has two outputs for remote switching. Have you tried using either of them yet on Gizmo?

  10. Bill Lentz says:

    I believe this is known in the cellular world as M2M data. There are reduced hidden M2M small data plans available from most carriers. They are usually negotiated by the device providers but not always, you may have to look for these small M2M plans M2M = Machine to Machine.

  11. Ben Ellison Ben Ellison says:

    Right you are, Bill. I believe that Siren Marine is using T-Mobile, which has apparently specialized in M2M small data cellular. I’m going to try AT&T with the SMS100, mainly because Maretron has already had success with their cards. If it works out as hoped I’ll be able to activate the card with no plan and auto pay .20 a message or add a message-only plan like 200 for $5 a month, which would be quite reasonable for boat monitoring.
    Mike, the Siren Marine system can activate relays but I haven’t tried it yet. I intend to but must admit that I’m reluctant to wire single-purpose switching, especially now that I know that the SMS100 will eventually be able to address the Maretron DCR100 N2K relay system that I’m already using on Gizmo.

  12. Peter says:

    I am struck by the fact that Maretron has seemingly stopped to document the PGNs used to configure their newer devices. Some time ago, they used to put all relevant documentation on non-standard PGNs in their manuals. Is this a change of policy?

  13. Mike Foley says:

    I use a DMK Box to get NMEA 2000 data onto the IP network such that I can monitor, alarm any data desired, anywhere in the world. When the boat has a WAN connection this is a very flexible solution.

  14. Ben Ellison Ben Ellison says:

    SMS100 testing update: An AT&T prepaid 3G SIM card does not work in Camden Harbor and vicinity. Despite what AT&T’s coverage map shows, this is an anomoly that I’ve seen before. And, despite a dicey coverage map, a T-Mobile SIM card does seem to work here. I haven’t set up alerts for the SMS100 yet but the test functions seen on the screen above worked fine.
    Buying and activating a SIM card without a phone is a chore, but I think I’ll end up with quite low rates. T-Mobile’s minimum prepaid plan gives me 100 SMS messages over a maximum of 90 days for $10 with auto refill as needed.

  15. Steve says:

    I ended up getting one of these, used T-Mobile, and while most things work, the status texts are not working. Still waiting to hear back from Maretron after more than a week.
    I wrote up my review at

  16. Ben Ellison Ben Ellison says:

    Thanks, Steve! I hope Maretron gets the Status text worked out, and there really should be other features like custom and automatically sent status messages, not to mention switching via text commands. I also enjoyed checking out the non-marine tech on your site.

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