Motion blue or ‘flicker’ is caused when the camera is moving quickly (for example panning a fast moving boat).
1. 180 Rule
One way to help minimise motion blur or ‘flickering” is to ensure you follow the ‘180 rule’.
The 180 rule is where your shutter speed should be set relative to the frame rate of your camera. So for example if you are shooting at 30fps, your shutter speed should be set to 1/60.
Lower the shutter speed and it may become blurry when there is movement, raise the shutter speed and you may find it gets choppy.
Adjusting your frame rate can also improve smooth video when moving the camera at speed.
2. Increase frame rate
Another tip is to increase your frame rate. For example 24fps are too little to achieve smooth video at speed. Try increasing your frame rate to 48fps (though you may have to reduce resolution) and see if makes an improvement.