I was on Amazon minding my own business when I came upon this little RC research submarine. What caught my eye is that it looked a lot like the Lionel one you see so often. I'm glad I found, because until I looked at it, I didn't realize how much I needed an RC submarine.
Anyway, nowhere did the ad tell how big it is (barely six inches, it turns out--much smaller than the Lionel submarine) but I took a chance. It is a nice heavy little thing, well made, and has three motors, blue lights in front that glow nicely when it is operating, and really does dive and turn left and right, etc. So far it has only explored only the bathtub, but it did a thorough job there!
I had some of Walter Matuch's depressed-center flatcars, labeled Coast Guard, no less, just perfect for it. I made small mounting block to hold it firmly. Just a nice little Saturday afternoon project.