Thanks for all the input!
I guess I always wanted one, but $400 is crazy!!! The profit margin must be HUGE. Other depth finders are $100 (which I'm thinking about looking into). I know that those won't integrate into the Spark's display, but still ... $400?
I'd like one, but for me, I've studied the local charts and where I ski, if its shallow, I can easily look down through the turquoise water and see the white sand.
Anyone, try an aftermarket depth finder?