Interactio bluetooth Optio fuel flow sensor for boats

Hailing from Victoria, Canada, is a plucky little startup company called Interactio. Co-founders (and engineers) David Burton and Roger Lines have a vision to bring Internet of Things (IoT) technology to the world of boating in a cost effective and simple way. Interactio’s first product called “Optio Fuel,” is the first completely wireless fuel flow sensor for boats that I have come across. It runs on a tiny battery and connects to your iPhone or iPad using bluetooth low energy technology.

Very soon I’ll test a production unit and report back on my experience. Until then, this is what I’ve learned about the Optio Fuel flow sensor and App…


Historically fuel flow monitoring on pleasure boats has fallen into one of two types. The first is the sensor and gauge package – like a Floscan system ($400US +). This is arguably the easiest installation (of the wired kind) because you get a complete package. Although it is proprietary, it isn’t dependent on any other system to work. A significant downside is that a dedicated gauge can’t be functionally modified in the future.

The second type is a fuel flow sensor that connects to a multi-function display (MFD) on a NMEA2000 (N2K) wired network. The Garmin GFS-10 is an example of this approach ($199US). N2K sensors incur the cost and complexity of the network wiring. Furthermore there is the reliance on spending many more boat dollars on a MFD.

A few years ago I asked my mechanic about installing a fuel flow sensor. His words of advice were:

“Boating is fun. You are better off not knowing how much fuel you are using!”

Most power boaters on smaller vessels are cost conscious and fuel is one of the largest expenses. I find it fun to boat and save money! My single engine 26 foot boat uses about 1300 litres per season. If Optio Fuel can guide me to save just 10%, it has nearly paid for itself in a single summer. I hope it can save me even more!

Optio Fuel Rendering
Optio Fuel CAD image

Eco Mode and EcoRange

Mercury’s VesselView partnership with Navico (Simrad, Lowrance) is perhaps one of the leading examples of engine integration with a multifunction display (MFD). VesselView has an Eco Mode which guides you to adjust trim and rpm to find that sweet spot where fuel economy is best in the target speed range. It’s a nice system but it is pricey and you need a Mercury engine.

On my boat I have a Raymarine c125 MFD with the latest Lighthouse software. It will show current fuel use and fuel economy. What it won’t do is guide you to throttle up and down to save money. Raymarine’s fuel manager feature can use derived fuel flow data from the engine to track fuel remaining without you needing a tank level sender. Unfortunately it treats all fuel used as if from a single tank. “Derived” means that an engine’s control unit has been pre-programmed by the manufacturer with specific fuel flow data based on engine parameters. It’s not the exact fuel flowing into the engine like with Optio Fuel, but it is reasonably close.

Interactio’s EcoRange feature shows range rings on a map like my Raymarine MFD. It also tracks fuel remaining and has a fuel manager type feature where you add fuel fills to keep it correct. To find your fuel-efficient sweet spot, Optio guides you to increase or decrease throttle settings like VesselView does.

Optio Fuel & App

Optio Fuel uses the smarts in your phone or tablet to create an independent low-cost and easy to install system. Functionality is easily upgraded and improved with an App update. At a price similar to the Garmin GFS-10 wired sensor, you get a complete stand-alone wireless package. Optio Fuel will appeal to smaller boats where fuel consumption is a concern and there isn’t a MFD on board.

My lead photo shows the Optio fuel flow sensor with the cover removed. Inside is a button type lithium battery. I’m told it will last an average cruising season. The sensor sleeps when it doesn’t detect fuel flow. This greatly reduces the draw on the tiny battery.

Interactio Fuel Sensor App for iPhone and iPadThe system learns a boat and adjusts a range circle on a map in the App that represents a best case scenario with the highest “on-plane” fuel economy. Another circle represents current range based on instantaneous fuel consumption. You adjust throttle until the two circles intersect. Even if the App isn’t connected, the Optio sensor totals fuel consumed. Fuel and range remaining update when the App re-connects.


In January, 2016, Interactio showed off a prototype at the Seattle Boat Show and were encouraged by the enthusiastic response. Fast forward to September when I sat down with Roger to discuss the product and get a demo.

Roger explained the design. Fuel is contained in a lower housing separated from the upper housing containing the electronics. A precisely adjusted oval gear pair provides positive displacement and forms the measuring element. Magnets in the gears send pulses to the electronics in the upper housing. The wireless fuel flow sensor then communicates via bluetooth to the App in your phone or tablet. Optio Fuel is supposedly accurate to within 1/10 of a US Gallon per hour.

This is by far the easiest fuel flow sensor on the market to install. No wires to connect. Just connect the fuel hose from your fuel filter to one side. The other side to your engine.

Since our meeting the IOS App has been approved by Apple (Android version to come). I’m pleased to report that Optio Fuel is finally here. Sponsors of Interactio’s Kickstarter campaign will get their shipments soon. I’ll get back to you with more information on Optio Fuel after I put it through its paces. Stay tuned!

Roger Lines at Interactio demonstrates the new wireless fuel flow sensor
Roger Lines demonstrates Interactio’s new Optio Fuel sensor

Added the following photo on Jan 31, 2017 from the Seattle Boat Show:

interactio fuel flow sensor


  1. I need an alternative fuel monitor. My fuel gauge is unreliable at best. I fish off shore in the Great Lakes and need reliability. Will your product provide this.