With the addition of the Olex SB module, and in conjunction with the vessel speed log it is now possible to detect and map water currents.
By analysing five NMEA data types - position, speed over ground, course over ground, true heading and speed thru water - the vessel drift related to ground is calculated and shown as a variable-size arrow pointing away from the vessel. The drift is assumed to be representative of the water current.
Accuracy of this additional module has proven to be very good and only limited by instrument resolution.