It's not rocket science... Weight of Ships v. Weight of Water?

Question: Did the Magdeburg Water Bridge have to be designed to withstand the additional weight of ship?

"Non-Engineer" Answer: No

Explanation: The Magdeburg Water Bridge only needed to be designed to support the weight of the water because a ship will displace an amount of water equal to the weight of the ship, regardless of how heavily a ship may be loaded.

Commentary: The Magdeburg Water Bridge is a navigable aqueduct in Germany that connects the Elbe-Havel Canal to the Mittelland Canal, and allows ships to cross over the Elbe River. At 918 meters, it is the longest navigable aqueduct in the world. Construction of the water link was started as early as in the 1930s but due to the World War 2 and subsequent division of Germany the work remained suspended till 1997. The aqueduct was finally completed and opened to the public in 2003.