Nelson, when the young captain of a small ship, boarded and captured two far more powerful enemy ships.

ECONOMIST: Patrick O��Brian

During World War II, radar was invented to detect enemy ships and aircraft.

CNN: STORY HIGHLIGHTS

But the system grew rife with abuse, since most privateers couldn't be trusted to limit their pillaging only to enemy ships.

NPR: Pirates 101: Fact and Fiction on the High Seas

In the game Steel Diver the 3DS functions as a submarine periscope, with the screen displaying a view of enemy ships on the surface.

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