Others can probably give you better opinions (since mine doesnt do so well at top speeds:rolleyes...but just make sure the roller on the trailer doesnt hiut the ducer when loading or unloading.

I leave my sensitivity on Auto and it re-adjusts to a lower setting when I'm at high speeds. I can still see a line of the bottom, but not in any detail at all. I am running a flat bottom Carolina Skiff and with it being completely flat there's no real pattern of the turbulance under my hull. Looks to me that where you have your 'ducer mounted at now it see's alot of water/air bubbles (turbulance) at high speeds.:rolleyes: JMHO.:o