Siren 3 Pro, boat monitoring evolved

Ben Stein

Ben Stein

Publisher of, passionate marine electronics enthusiast, 100-ton USCG master.

12 Responses

  1. Bob Easterday says:

    One more item on the plus side. I’ve found their support to be top-notch. When I was setting up my czone system and interfacing it to the Siren, I had issues with Siren not recognizing the Contact 6 switch. When I contacted them thee told me they had not tested that particular device, but that they would work with me to attempt to figure out the problem.

    Work with me they did. One of their support techs patiently walked me through the process and even verified my configuration file. The issue turned out to be old firmware on the Czone product and I can now happily report that the Siren does indeed work with the Contact 6 interface.

  2. Grant Jenkins says:

    Interesting article, Ben.
    I’m sure Siren makes decent quality stuff – but the subscription-based model is a little irksome, especially for those of us who’ve already invested in Cellular and/or WiFi systems to stay connected to out boats. By comparison, Victron provides a subscription-free portal where you can access a lot of the same data you describe in your article, if you have any of their hardware (eg, Cerbo GX, etc).
    The other “elephant in the room” about remote monitoring that rarely if ever gets mentioned – How exactly are you going to power/wire all the sources needed to make this work?? Specifically, many boaters follow the recommended best practice of turning OFF the battery switches when leaving the boat unattended, especially if we’re talking weeks or months. So – is your NMEA2000 network powered off the 24 hour bus? How about your GPS, or AIS? Or Wi-fi and router? Or your engine gateways? Unless you make a concerted effort to address this, a lot of your data is not going to be available remotely. And my understanding is that ABYC has a very short list of “approved” devices that can be wired to a 24HR, unswitched bus, although I admit I can’t really figure out why they would care one way or the other, as long as everything as proper over-current protection.
    The alternative, or course, is to just leave the battery switches ON all the time – but I for one am not prepared to do that. Seems like something that needs to be considered before planning a complex monitoring system….

  3. Ben Stein Ben Stein says:


    Looking at these products from a value perspective it’s tough to beat Victron. But, in order to have a fully monitored boat with only Victron equipment, you’re looking at a fairly large investment in their equipment. Though, with the benefit of no ongoing subscription costs.

    As for the always-on issues, I think Siren probably has some pretty good answers. First, the wireless sensors are battery-powered and don’t require any external power. The main unit does require power and although I haven’t yet measured the S3Pro I can tell you the MTC was a pretty small power consumer. I’d expect similar from the S3P. There is a built-in, rechargeable battery that will run the S3 for several days without external power, though that’s certainly not long enough to just throw the battery switches off and leave the boat.

    Although for my use, on my boat, I wish Siren read more data from the NMEA 2000 network, I think that for the concerns you’ve mentioned their limited reliance on N2K data means that powering down the N2K network when you leave the boat only means missing engine data (those shouldn’t be running when you’re gone) and tank levels. That seems an acceptable tradeoff.

    One more thought on the subscription model and cellular connectivity. I have several monitoring products on Have Another Day, they’re a mix of cellular and WiFi-based devices. I really appreciate the cellular devices because they’re stand-alone. They’re not reliant on a separate router, radio, etc being powered up and properly connected. When I’ve left my boat for long periods of time it’s not unusual to suddenly get a flurry of alerts that a bunch of devices have disconnected. If it weren’t for the cellular devices I wouldn’t know what was happening.

    The usual case is that internet connectivity has failed. The cellular-connected devices let me take a look at status, see that shore-power is still active, batteries are still charged, bilge pumps aren’t running, etc. Without them, I’d probably have to have someone go check on the boat. If I only had one monitoring device on the boat it would surely be a cellular model.

    -Ben S.

    • Grant Jenkins says:

      Good points Ben – but I’m still not clear. You say “the main unit does require power…” So, did you wire it to the 24HR bus, or do you just leave your battery switches on all the time? At a minimum I think I would want GPS and AIS data for anti-theft purposes, so there’s every possibility of losing those without the NMEA 2000 network, depending on a vessels particular equipment and configuration.
      I’m not saying it can’t be done – but my feeling is that a lot of folks don’t consider all the pieces and power sources until they’ve committed to a system, and then when they realize it’s not going to give them everything they planned on, just resign themselves to leaving the battery switches on all the time. That’s a pitfall I don’t wish to fall in to…

  4. Ben Stein Ben Stein says:


    I do have my S3P connected directly to an always-on circuit (with appropriate overcurrent protection of course!) But, currently, Siren doesn’t support relaying AIS information via NMEA 2000 or otherwise. There’s a built-in GPS receiver for position. If you mount the S3P in a location where it can’t find a clear view of the sky you can connect an external GPS antenna, but that’s not through NMEA 2000. At present, Siren doesn’t pick up location information from N2K.

    I do think Siren has thought through many of the issues you raise. It seems only logical that a monitoring system will need to be powered at all times and such should be engineered for maximum efficiency.

    -Ben S.

  5. Howard says:

    I hope Siren Marine offers an attractive upgrade path for current MTC users. As the various cellular network providers shut down their 3G networks next year MTC units will start to lose network connectivity and become useless. Per the support FAQ Siren uses Vodaphone SIMs which roam to AT&T and T-Mobile in the USA. AT&T is scheduled to shut down 3G in Feb 2022. T-Mobile has scheduled their 3G shutdown in July 2022. The carriers are doing this to free up spectrum for additional 5G network bandwidth which is understandable.
    I contacted Siren support about this and they said I should upgrade to a S3P and can get $100 off right now. However, this is only part of the upgrade. MTC wireless sensors are not compatible with the Siren 3 and need to be replaced. I have 2 high water sensors. One could be replaced with a wired float switch since the S3 supports 2 wired inputs (I am also using the wired high water input on the MTC so the second S3 input is available) but an additional $21 cable is needed on the S3P to access the second high water input. I also have a wired temp sensor connected to my MTC, this would have to be replaced by a wireless temp sensor for the S3. I monitor 2 bilge pumps with wired connections on the MTC, the S3 does not support this, so 2 more wireless sensors would be needed. So I am looking at a minimum of 4 new wireless sensors along with an S3 to replace my current MTC setup at a cost of over $1200.
    On my previous boat I installed the original Siren Marine Pixie. When the MTC was introduced Siren had an attractive upgrade plan, if I remember correctly it was 1/2 price and there were not any sensor issues, so it was an easy upgrade.
    I hope Siren does something soon for MTC owners. Mine has been installed for only about 3 years which is a short lifetime for marine electronics.

  6. Bill F says:

    Regarding mounting of the main hub, I was thinking of the engine room. The boat is in SoCal, but in the Summer the ER probably gets up to about 100F or more. Any issues with this?

    Where are most people mounting their main hub?

  7. Jon Hill Jon Hill says:

    Siren has just come out with their MTC replacement deal: A Siren 3 Plus with two wireless sensors for $475 and additional wireless units for $109. If you were using the wired bilge pump inputs on the MTC it takes two wireless inputs on a 3 Plus just to do the same thing so this isn’t much of a break. They also want the MTC returned before they send you the 3 Plus so there will be a certain amount of unmonitored time involved while the annual subscription clock is still ticking.

  8. Howard says:

    I talked to Siren Marine today about upgrading my MTC. The Siren 3+ has built in GPS, cellular, and wireless sensor antennas like the MTC. It has one 12 pin wired connector, (the 3 Pro has two for additional I/O). The 3 plus does have a single bilge pump wired input, something the Pro does not have. I was told this was to make the Plus closer in wired capability to the MTC. It is also possible to get the 3+ before returning the MTC if you call them. You do need to proved credit card info, they will charge you $400 if you fail to return the MTC. If you want to purchase additional wireless sensors beyond the two included with the offer you will need to call them to get the reduced price, they need to be ordered with the S3+. I got on the list for an upgrade but still need to call back to order additional wireless sensors, my boat has three bilges. I am also thinking about the usefulness of measuring cabin temp, on the MTC this was an inexpensive wired sensor, on the S3+ it is a $109 wireless sensor. They expect to start shipping in mid April.

    • Matt says:

      This whole end of life and upgrade pathway has really left a sour taste in my mouth in regards tot he company. Especially now that they are owned by Yamaha

    • Howard says:

      I just received the Siren 3+ upgrade for my current MTC. I will be installing it this week so I can return the MTC. Fortunately my MTC has continued to get good cellular connectivity even with most of the 3G networks having been shut down.

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