RE: What is the range of a Shockwave 36?
Figure a 1/4 mile radius, a lot further than you'd want to take the boat out. You can have a lot of fun with it by not going out any more than 300 feet in any direction. I don't go out any more than what I want to row to get it.
For range checking your radio, have yourself or one of the kids walk about 60 feet away with the transmitter antenna all the way in, not extended and see if you can still operate it, wiggle the rudder or throttle. Keep it in far enough so that you can clearly see what the boat is doing. I learned this the hard way by trying to fly planes. There are several that I never found.
The retrieve question has been answered a lot in here, go back a few pages if you need to or do a search.