I have the original radar on my boat (2004 Hewescraft), but I have no idea how to operate it. I have tried many times and I don't know if I'm using it correctly, and I can't really tell what I'm looking at. There are a bunch of buttons with letters/numbers that I don't recognize. Is there anyone that can help me with this? I am going to buy a Garmin 740s this month and I am almost ready to pay an extra $1000 for the garmin radar that shows on the screen because I don't know how to work the one that is on the boat. Any ideas?