Umm...330 billion cubic feet per hour for one tube? You realize that is roughly 91,000 cubic feet per second? How large of a diameter do you think one of these things would be?

Next question....you have a figure of 5mph in there. Would this be the rate at which the water flows from the bottom to the surface, or which the gulf stream flows at ahead? However, what really matters, is what happens when you move enough water from the bottom of the ocean to the surface so that the gulf stream shuts down all together? You must realize that as the gulf stream moves north, it interacts with the cool Labrador current in the northern latitudes. This mix of warm and cool water currents causes the currents to behave in a certain fashion. What do you think is going to happen when the cool water you release into the gulf stream cools faster then normal up the east coast and interacts with the very cold water of the north? I'm not sure, but I certainly don’t want to test any theories.