Garmin Speed
Garmin Speed
Garmin pairs decades of GPS heritage with some of the most capable sonar and chartplotting on the water. This is the Garmin speed range: speed and log sensors and displays.
Browse the full Garmin range or Speed from every brand.
Paddlewheel or ultrasonic: which speed sensor
Garmin's speed range covers both traditional paddlewheel sensors and ultrasonic, through-hull options with no moving parts, and the choice usually comes down to how the boat is used. A paddlewheel sensor is simple and inexpensive but needs periodic cleaning, since weed and growth on the wheel will show as a falling or erratic speed reading long before anything actually fails electrically. Ultrasonic sensors avoid that maintenance but cost more and need a flatter run of hull to mount correctly.
Either sensor type outputs speed through water rather than speed over ground, worth remembering when comparing the reading against GPS speed, since the two will differ by however much current or leeway is acting on the boat at the time. Fitted correctly and calibrated against a known GPS speed, a paddlewheel sensor is generally accurate enough for log and fuel-consumption calculations on most cruising boats.
