Meet Optio Fuel: an easy-to-install sensor that mounts in your engine room and ties into your fuel line to help you save fuel while cruising on your boat. Optio Fuel calculates the highest speed you can go for the least amount of fuel and displays it on your iOS device. The companion app displays your cruising range on a map, distance to empty, and other fuel consumption data.
Optio Fuel can be installed in minutes. It has a battery that lasts up to a year. More information is available on Kickstarter.