I used it in the Atchafalaya river and it seemed to work well. Just remember if the transducer is drifting, the image your seeing, is well behind the transducer.
I read one review that said it stopped working after 10 uses in salt water. I only use mine in fresh water. Garmin makes one for the same price that works in salt water but you need to use an iPhone for the screen.
The maximum distance is about 262FT/80M.
Following is one comment from our customer reviews of this product. Hope it helps."I did have to change the background to white to see the screen in the bright sunlight. The white background makes it very visible. "