this is what I've read narrow cone angles concentrate the most power within a smaller area making it easier to determine the precise depth fish are holding at.wider cone angles cover more area and thus see more fish but you can't determine precisely where there holding.I think a wider angle will show more bottum and thats were 90% of fish are the shallower the water the less bottum you'll see expecially with the smaller cone I'd try what you have if you don't like it get the bigger one