Here are pics of what i use and how I set mine up.
All the equipment is portable and tidy.
Ball mount on front riveted into my board.
Ball mount riveted on seat for sonar unit.
Where I put my battery (usually in my box but this is just to show you)
This is the transducer on the yak but in the up position (It drags on my trailer so I put it down once in water)
The transducer down (not all the way as I said)
And the unit on my seat. As you can see plenty of room to lower it out of the way. But I have never had the need to lower it. I always have it on and see everything up close!