Answers (2)
That depends on what you think makes a zone. The sun in the Caribbean Sea warms the water so it rises. Electric current from the sun makes the water in the north areas flow eastward, same as it makes the jet stream blow eastward. So there is an immense current in the ocean, flowing north, east, and then south. New York City is bathed in warm water, but England is bathed in cold water from the Arctic Ocean and the North Sea.
Now how much of this do you consider to be a zone?