Most likely, the boats movement is smooth enough to separate the actual movement from the short vibrations (fake) through the accelerometer.
The first thing to do - is to decrease the motion start detection timer (setparam 19001:1) and increase the stop detection time (setparam 19002:300).
Also, please, disable sleeps mode if its enabled now.
Additionally, we recommend disabling the static navigation filter (if the previous step did not work): setparam 106:0
These recommendations were made only based on your screenshots and a short description of the problem. For a more detailed analysis, additional information is required. If these recommendations do not help you, please write again.