The Port refers to Port Glasgow, a town in the west coast of Scotland. People who aren't local tend to confuse Port Glasgow with the city called Glasgow, so the Port works as a nickname to avoid this confusion.
Port Glasgow is next to Greenock and smaller places like Kilmacolm and Langbank. It's home to the Port bird.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.