Today's Geo Quiz is passing through.

Work began just days ago to expand the 48 mile long Panama Canal. The international waterway is not the world's longest, nor the busiest canal. But it does allow ships to pass through the Isthmus of Panama.

It's a shortcut that shaves nearly 8,000 miles off a voyage that would otherwise have to go around Cape Horn at the southern tip of South America. 14,000 thousand ships pass through each year.

The $5.2 billion expansion project to double the size of the canal won't be completed until 2014. In the shorter term... the much shorter term... we need help with directions.

We want to know: Which direction do you sail through the Panama Canal? When a ship pass between the Atlantic Ocean and the Pacific......which direction does it go?

Time to get your compass out and see which way the arrow points.