the bottom is most of the problem......if you have a weedy bottom, sometimes it is very difficult to discern what is tru bottom and what is vegitation.....If you have zoom, it would show you SOME better seperation, however it may not be so clear that it jumps out at you as a fish. What I look for (with zoom) is a seperation from the bottom, or movement when jigging. depending on your depth...you may not gain much from the zoom. My recommendation is to find someone around the area that has a FL-18 or FL-20 and do a side by side comparison to see if the zoom would benefit you...dont forget most places allow you to return products you arent happy with if you buy it and it doesnt meet your expectations....jsut make sure their return policy before you buy if you are thinking you might need to return it.