A great use for sonar

I've been musing for a while trying to come up with an appropriate submarine-related term about ultrasounds. A periscope in the womb, perhaps? Or maybe "returned ping, target acquired!" Whatever the analogy, I marvel at the technology that allows us to peek at a child only six weeks after conception.

There he or she is, the latest submariner in my family. Already swimming around surrounded by water, getting used to the environment. And not scheduled to "surface" until August!