Container Ships are beastly moving mountains. They have a huge amount of inertia so their courses need to be planned well in advance. If you are another type of boat, watch out! The container ships can't change their course, so you'll need to get out of their way!
If you're interested in learning more about life on board a container ship, check out the ship transport wikipedia page and the container ship page. Also if you've ever wondered how to get a job on a container ship, wonder no more.