I agree with the 5 times the waters depth for identifying what species of fish you are looking at for sure, because everyting in the image would be proportionally correct! But just generally scanning if its deeper than 5-6 foot deep I keep it at 75 feet at least. But no more than 100 feet. This way things in the screen are indeed less detailed and visiable but still visible enough to catch my eye. Then I will hone in on it once I have found it. Scanning at 30 feet out to the side doesnt give you much more of an advantage than old school technology inmy opinion. I was doing 4-5 times my depth when I first started, and my buddy ABH explained to me the way he does it. Made since, and I get way more use out of my side imaging now!