There are two ways the app can measure current, one with the phone in the boat and another with the phone on the measuring stick or phone connected to the device on the stick.
The phone is in the boat
You can measure current with anything (stick, bottle, banana peel…). For this mode, you need to set the “Two Points” mode in settings. Simply press start at the moment you put the measuring stick (or whatever you use as a measuring device) in the water. When you come back to pick it up, press stop and you get the speed and bearing.
Make sure when pressing buttons that your phone is directly above or as close as possible to the measuring stick.
The phone is on the measuring device
“Smooth” mode starts measuring once you press ”Start” and takes all the points until you press “Stop”. It gets the most common speed and direction, so once you pick the device, it will still show good values for some time.
It is even more reliable than the 2 points mode, since it uses all the points collected, but is harder to implement to have the device in the water.
GPS Accuracy
It is important to give a GPS a bit of time to get high accuracy. Modern phones, especially on the open water, would pick up all the satellites quite quickly. Wait a bit till the “Acc” field comes to lower values. Also, it helps if your phone screen stays on during the measurement. You can check on the track view if the dots are following your movement or are still jumping around if the accuracy is not high. We recommend for measuring the currents up to 15m/min, 60-90 seconds of measurement should be good. If currents are strong, 30m/min and more, even 30 seconds or less would be enough.
Compass Arrow and Track Window
The arrow at the bottom of the measuring screen shows the compass direction of the measured current. If you place your phone horizontally it should show the way the current moves. To make it more accurate, move your phone in a figure of 8 a few times to calibrate the compass.
Track window with dots shows your device path. Red-letter S is the first location considered, and blue letter F is the last one. Here you can catch if there were some GPS errors if points are not shown as your phone was moving.
Measuring Units
You can change measuring units by pressing the unit button on the measuring screen or in settings. Supported are m/s, knots, m/min, and cm/s.
True and Magnetic Reading
Both true and magnetic readings are supported. You can swap by pressing “mag” or “true” next to the direction reading.
Showing From or To Bearing
You can switch between showing the current direction from or to. Just press the “From” or “To” button left of the bearing value.