Depth/fish finder for collision avoidance?

[Flashpoint]

So I'm going to electrify one of my kayaks, installing a permanent or semi permanent trolling motor. Not only am I lazy, but I like to sneak up on birds/turtles/gators, etc. for photo opportunities and waving around paddles tends to get their attention.

Obviously a trolling motor will require more depth than the kayak alone to operate properly, and I'd like to know in advance if possible when I'm approaching a submerged obstacle. Do any of them look a little ahead, or could I angle the transducer slightly forward facing or would that screw up everything? I have very little experience with using the modern ones, last one I used was a spinning ring of light, lol.

 

[Slacker]

Super short shaft with a prop guard is what I'm thinking.
Leave it unlocked so it can ride over most things that you bump.

 

[mj1angier]

Here is a UK write up about some. http://www.pbo.co.uk/gear/5-forward-looking-sonar-tested-29321

But I don't they work well in shallow or muddy water.

Are you just trying to be sneaky or are you just worried about damaging the motor?

 

[Beef15]

If you angle them your depth reading gets inaccurate pretty fast as I understand it, your app seems to require accuracy, that shallow I think they're all pretty lame though, just not enough time.
No experience with side or front scanning.
I'd leave the motor unlocked and shoot thru hull mount the transducer in the bow, kill motor and pop it up as required, it'll pop itself up if you're not paying attention.

 

[Flashpoint]

The possibility of employing a submerged wire "curb feeler" from the bow has also crossed my mind, though I'm sure there would be some drag.

 

[Daedalus-NC]

What you need is a sidescan sonar, designed for that very purpose

https://www.humminbird.com/Category/Technology/Side-Imaging/
https://buy.garmin.com/en-US/US/p/528825


EDIT: Scary - that was my post #666 !