SmartThings keeps the boat warm during winter

I have an extensive automation system in place at home and the family cabin, and recently started realizing I had done next to nothing on Grace. I use SmartThings for most of the automation, and thought “why haven’t I done anything with this technology on the boat?” So I did.

What is SmartThings?

I backed SmartThings on KickStarter back in 2012, and was excited when the product shipped. The core of the product is the hub which speaks multiple protocols so it can interface and control both SmartThings-built and 3rd party devices. These include Zigbee, Z-Wave, and other IP based protocols.

SmartThings hub

SmartThings hub, courtesy of

The hub connects to SmartThings branded sensors as well as hundreds of other 3rd party sensors and systems. At home, we have 5 motion sensors, 6 multi purpose/door sensors, 6 various outlet plugs, 3 presence sensors, and a handful of other random things. Some use Z-Wave, while others are Belkin Weemo switches. In addition, SmartThings interfaces with our Amazon Echo, Philips Hue lights, and Sonos sound systems.

SmartThings at home

SmartThings at home

The level of automation we have in place at home is pretty crazy. There are routines for when we go to sleep, wake up, or arrive at home that turn security sensors off/on, lights up/down, and even start playing music at different times of the day. One of the most convenient parts of SmarThings is that all of the various home automation technologies are unified under one app – Sonos, Philips, sensors, etc. – so that all of the family can control things easily from one place.

Most recently I setup a Philips Hue light strip in our bathroom and a motion/light sensor that triggers a warm red light only at night when the lights are off so you can find your way around. Grace’s automation will be simpler than that based on the available space, sensors, and needs.

SmartThings Home Monitoring Kit

SmartThings Home Monitoring Kit

SmartThings comes in a few flavors, one of the most popular being the Home Monitoring Kit. This comes with a hub, outlet controller, motion detector, and two multi purpose sensors. This is what I purchased for Grace.


SmartThings architecture overview - courtesy of

SmartThings architecture overview – courtesy of

One of the things that drew me to SmartThings was their architecture. Not only was it very well thought out, but they provide a full developer API and web login to be able to connect your own devices, write your own automation, and so much more.

I find it very helpful when debugging things to login to the web site and watch as activities flow by. You can tell if you’ve done something wrong very easily.

SmartThings container hierarchy - courtesy of

SmartThings container hierarchy – courtesy of

The overall design is really simple – start with an account, add locations, build rooms or groupings, and then your devices.  Makes it easy for managing all of the bits like you would think about a room or space.

The Sensors


Multipurpose sensor

Multipurpose sensor

The multipurpose sensor is generally used as a way to detect a door opening. I’m using it on Grace as a way to detect temperature in the main salon and owners cabin. It can also be used to detect vibrations.


Motion sensor

Motion sensor

I use the motion sensor to detect whether someone is inside the main salon. It is mounted above the door to the v-berth facing back towards the cockpit door. When I am away (as detected by the presence of my phone or presence sensor) the security system arms and watches for motion.

Power Outlet

Power outlet

Power outlet

The power outlet is driving an electric oil-filled radiator heater which is plugged in to a GFCI protected outlet near the v-berth.


Installing SmartThings on Grace was pretty easy. I chose to use a DC-DC buck converter to take 12v from the battery bank and convert it to 5v, which the hub requires. This will allow me to run the hub and wireless sensors even without AC power.

The hub requires an ethernet connection, which is a bummer as I have limited connections on that front. I hope they make a WiFi enabled version in the future.

The rest of the sensors are battery powered and were stuck in place with adhesive.

Heat Control

Using the power outlet combined with the multisensor in the main cabin, I used a simple set of logic to ensure that the heater was always on if the temperature was 55 degrees or less.


Automation settings for Main Cabin sensor driving the Heater outlet


Real time status and wattage

Real time status and wattage

Now I can see if the heater is on, the actual wattage being consumed, and turn it off remotely.

Heater wattage records

Heater wattage records

You can also see historical wattage records, and other state history.

Main cabin temperature

Main cabin temperature

Viewing the main cabin multisensor, you can see the current temperature, and history as well.

Heating the boat in the winter is important to be done safely and in a controlled fashion. Oil-filled radiators are very reliable and safe, but I hate when they are over heating the space or left on needlessly on warmer days. The automation I’ve put in place with SmartThings will allow me to control it more closely, turn it off when I know its no longer necessary, and I also have a full security system as a side benefit.

There are a lot of other things I’d like to automate, including bridging SignalK alarms and alerts into SmartThings, or perhaps even a full API link between the two. For now, being able to manage the heat remotely is a great first step.


About Steve Mitchell

I live in Seattle, WA and love sailing, technology, & playing and composing music. I started playing the piano when I was 3, and ended up figuring out many other instruments along the way. I'm an avid sailor and have a 2000 Beneteau 311 named Grace, and sail it whenever and wherever I can.

  • captobie

    This is one of those “duh, why didn’t I think of that” moments for me. I don’t really have a lot of interest in these systems for my home, but for keeping tabs on the boat during the winter I can see a lot of value. This may get added to my project list. Thanks for writing this!

    • Steve Mitchell

      Glad I could help! I use so much of it at home, I was shocked I didn’t try it on the boat. Just in the last few weeks it’s been super nice to have it setup on the boat and I’m already thinking of other ideas…

  • Stacey Hoopes

    This technology is pretty cool Steve – thanks for sharing your experience!

    I’m curious if you have any idea how to potentially use this in our situation. We are cruising in Malaysia/Thailand and are interested in creating some sort of alarm/alert system if someone tries to enter the interior of our boat. Because it’s incredibly hot, we always leave the cockpit door out – with just a mosquito net covering the companionway. About 2 months ago we were boarded, but thankfully they didn’t try to come down below (I think it was just curiosity and opportunity – looking for something quick to take on deck – but since everything is locked, we didn’t loose anything). This got us thinking about security and perhaps some sort of alert device near the companionway as it’s just WAY too hot to close everything up at night (and we prefer to leave it open for ventilation).

    The issue with standard devices we’ve tried in the cockpit is they tend to be set off by the motion of the boat moving at anchor. We’d like something that would potentially make a LOT of noise (to scare the intruder, AND alert us). The solution would have to be low amp draw (since we’re at anchor 99% of the time and make all of our own power), and able to handle a high humidity environment – while not being so sensitive that it goes off every time the boat swings or a bird flies by. We’ve tried some of the less expensive “home depot” battery powered type of solutions – but they go off constantly. Any ideas on if we could use this technology in a way that might work?

    Thanks again for the post!


    • Steve Mitchell

      Hi Stacey,
      Thanks for your comment!

      Based on your needs, I’m not 100% sure that SmartThings or something like it would work. I definitely know you could leverage their motion sensor devices, or one from a 3rd party that has different properties, that would be a narrow beam and not be disturbed by the motion of the boat. I use their stock one which is pointed directly out the glass cockpit door (huge) and it has never been set off by the covers on my steering station (big floppy thing) or outside influences. However you would definitely want to test this in your situation.

      The sensors are all battery powered, so you would not have any amp draw there. The SmartThings hub itself requires constant power, or it can run off of internal AA batteries for a time before running out of juice. I’ve not measured how much it draws but can do that sometime soon if it’s of interest.

      The other challenging thing is that for this all to work, SmartThings requires a 100% on Internet connection. Are you at moorages and places where this would be possible at night?

      The only other thing I’d be cognizant of is the sensors themselves. They are not that expensive, and designed to handle a wide range of temperatures and humidity, but they are not marine grade. I’m sure after a year of use in the type of weather you’re talking about, you might have to consider replacing the most exposed one.

      Another thing to consider is a completely standalone security system like SimpliSafe. They use cellular to notify you, and have a lot more features built in as a security system. Still all wireless, and no huge monthly fees, but more purpose built for security. I see a lot of home users of SmartThings in the forums and elsewhere go this route when needing a rock solid security system.

      Hope this helps!

      • Stacey Hoopes

        Thanks very much for the information! It’s true that we don’t always have internet since we stay in some pretty remote areas. We have some sort of connection (via our iPhone) about 85% of the time, but it’s not unlimited, so if the system was using much data, that would be an issue as we purchase by the Gig. Having to replace annually would be fine (safety is worth the expense!) but the constant power draw could also be an issue, unless it was fairly minimal. I can’t imagine it using that much power. I assume we could just plug it in when we needed it at night, right? We will check out SimpliSafe too – thanks again for your help! 🙂

        • Steve Mitchell

          It doesn’t use a ton of data as long as you have things configured OK. Motion sensors and other things like that sometimes can be super chatty, but it’s pretty small updates out to the cloud. The bigger issue for your setup is the lack of a permanent internet connection. I think some of the security systems out there can be used standalone without an internet connection, which are likely a better choice for your situation. SmartThings hub doesn’t seem to draw that much at all, so I don’t think it would be that bad if you just had it on at night.

  • Larry

    I use 110v thermal outlet plugs that I sent outside the boat in a protected area. It powers an internal heater starting at 35F and shuts off when 45F outside.

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