Binoculars

Growing up with a sailor, you learn your sailing skills rather quickly. Capsizing in Maine waters is something you would NEVER want to do, for example.

But this is about binoculars. In the great war, the Navy specifically settled on 7x50s. The 7 is the magnification, the 50 related to the light brought in.

You are probably thinking, a lousy 7 magnification? Here is where the genius came in.  Ever try to use binoculars on a moving boat in waves? The 7x50s were the perfect combination of magnification and actually trying to hold things steady enough to see.

Genius.