navionics Platinum Overlay

[Eesctom]

I got the boat back and I've been screwing around all night in the garage with the GPS function on the Hummnbird unit. I see streets etc. but how do I get to the overlay feature that will show me some google earth type images over the map? I have the Platinum Navionics chip and I just put it in the unit. I tried scrolling up to lake Okeechobee to see if it would show it there but no dice. I watched some tutorials on you tube but they all have the giant units on saltwater boats so it didn't translate that well but they showed one part where they guy scrolled the cursor and then did the overlay to see actual aerial shots. Can't figure it out on my unit so I'll call Navionics tommorow but anyone else have this issue?