Looking for a new fish finder

[PutteringAlong]

I have a lot of the same questions, but being impulsive, I picked up a half-price Eagle FishMark 160 at Sportsman's a couple of weeks ago. First, I had to figure out how to transport it, and then I needed a way to tell the wife about the new equipment. I started with the outfit, mounted it in a spare tool box big enough to anchor the battery and hold the PVC pieces. I thought it turned out pretty well so I showed the little lady...she laughed like hell! Said I'd been watching too much Red Green and so she went and got a piece of duct tape to finish it off. (see attached pictures). Anyway, the PVC pieces come apart and fit inside. The box is a little large for a small ice hut and the weight of the finder closes the lid without the piece of wood wedged in to hold it open. You can laugh too, I'm used to it by now.[crazy]

My question, actually questions, have to do with operation of the unit. The instructions are vague at best in describing what some of the features are used for. If anyone is willing to comment I'd like to hear suggestions for setting the following features:

Sensitivity: how high/low is best?
Grayline: This is perhaps the most confusing (to me) feature. What is it for?
Chart Cursor: Seems to be a line through the middle of the screen, what is it for?
Surface Clarity: Is this different for ice and liquid water?
ASP: Off, normal, or high?

Most of the other options are easier for me to understand. Thanks in advance for any suggestions!
[signature]