Look at a polar vision from Strikemaster. I use one, works great. It uses 2 9 volts, but mine is an older version, the new one now only uses one 9 volt, and now gives you air & water temps. It also alot smaller than it used to be. (about the size & shape of a large flashlight)You basically wet the surface of the ice, and couple it to the surface, and shoot. It will also flash back depth of fish, if they are present, I think the unit costs about $120. Vexilar, and I think Marcum make similar units. Or you can do what i mostly do now, is use a gas auger a cut holes everywhere, lol.