Motion Tracking for Kayakers Too: Xensr Air
For the past 10 months I’ve been using a sports motion-tracking device called the Xensr Air 3D GPS (pronounced “sensor”), the product of a Green Bay, WI-based company. As company founder David Troup once told me, “In order to make it unforgettable, we made it unpronounceable.” The Air is touted as the world’s smallest and smartest 3D sports motion tracker supporting more than 25 sports. (Full disclosure: David is my wind-surfing, kite-surfing, stand-up-paddle-boarding next-door neighbor. I have received no compensation to review his company’s products.)
Lightweight and about the size of an Oreo, the Air is a device that mounts on the athlete’s gear, whether that be a surfboard, bike, skis, and yes even a kayak. The retail package comes with multiple mounts that have adhesive backs.
By placing a mount on each of your outdoor toys, you can easily transfer the Air from one to another. Sometimes when I go for a run I even stick the Air in my pocket to record distance and average speed.
In addition to recording GPS and three axis of motion, the Xensr Air transmits real-time sports motion information over Bluetooth to apps in smartphones, Android Wear smartwatches, action cameras like the GoPro Hero 4 and other devices. If you’re an iPhone user, the GoPro connection is interesting. Here’s how Xensr describes it:
When you head out, sync your Xensr Air and GoPro with your Xensr app on your iPhone. While your camera sees all your action, your Xensr Air knows everything you do. Jumps, airtimes, speed, etc. and when you’re finished, just press “stop” and your GoPro and Xensr Air stop recording. Now you’re ready to make a video. But, instead of spending hours and hours editing video back on your laptop, or transferring files, uploading to the cloud, you use the Xensr’s OneTouch video capabilities right from your iPhone. In seconds the app will create a movie for you, complete with data overlays of your best jumps and airtimes, and you’ll be sharing your epic session before the dust even settles on your gear.
The Xensr Air does not measure height. Instead, it sees an acceleration in a certain way for a certain time and then calculates the height. It also contains a GPS receiver for measuring speed, distance and elevation. Other than blinking lights to let you know it’s working, the device has no display. You view results on a paired device or upload your session data to the Xensr website for a graphic view. After uploading, you select your particular sport from a list and the website pulls the appropriate parameters for your session data and runs them through an algorithm customized for that sport.
You choose whether to make your sessions publicly viewable. Click on the links below and you’ll be able to view and interact with a few of my public sessions. Hint: For the full motion effect, mouse over the bottom of the map view and click on the “3D” button.
You can also export your sessions to GPX or KML files. These files can be used in popular social fitness programs like Strava and Endomondo. Or import the GPX files into Excel to make your own database.
The Xensr Air was originally developed to serve windsurfers and kite surfers so they could measure the height and duration of their jumps. That’s why you’ll see much of Xensr’s marketing imagery aimed at those sports. However, I’ve found the device also provides interesting information for kayakers — both whitewater and sea kayaking.
For Whitewater Kayakers
Whitewater kayakers who mount an Air on their boats can record and view a GPS track of the line they chose through each rapid. They can also view a 3D representation of a kayak that mimics every movement of your boat in three axis. Below is a motion-capture video of whitewater kayaking. I shot this last Saturday on the Wolf River in Wisconsin as I did a couple of spins. Later I used screen capture to place the Xensr website display side by side with my GoPro footage.
Here’s another example. Last month at Wausau Whitewater Park I mounted an Air on the playboat of more-accomplished-than-me freestyler Rick Rassier. This shows full three-axis of motion on a playboat including loops:
For Sea Kayakers
For sea kayaking, the Xensr Air performs some of the same functions as my Garmin handheld GPS receiver: route, average speed, total distance paddled, maximum speed, etc. However, a handheld GPS receiver has one big advantage over the Air for sea kayaking: the Garmin can be used for on-water navigation because of the built-in map display. All you see on the Air are blinking lights.
That disadvantage aside, there is a unique and fun benefit of the Air for sea kayakers. If you like to use your boat to surf big waves, when you get back home and upload your session to your computer, you can choose “surfing” mode instead of “kayak” mode. Your session view will count your total surf attempts and show you which ones were successful. At least which ones the algorithm thinks were successful. It also displays paddle time versus surf time, length of each wave ridden, fastest speed per wave, and gives you a 3D replay of your board (in my case, boat) motion.
Xensr says surfers are also able to view the size of the swell that passes under their boards. So far my Xensr Air has not recorded wave heights in my sea kayak. It’s possible that the waves I have recorded have not been tall enough. Or it may be due to the positioning of the Air on my kayak. In my feedback to David I mentioned that sea kayakers love to brag about wave height so I’m hoping further refinement of the algorithm will make it possible for me to accurately record — and yes, brag about — wave height. Once Xensr nails that capability, I predict many sea kayakers will beat a pathway to their door whether or not they surf. It’s a rare thing to meet a Great Lakes sea kayaker who doesn’t overestimate the size of waves.
So how much, you ask? When I purchased my Xensr Air last year, the retail price was $249. Xensr recently announced its 2.0 version of the hardware and reduced the price to $199.95. To keep product performance and features current for all users, the company continually offers free firmware downloads.