> But a storm surge would be unpredictable, right? No we know what sort of storm surges are 10, 100, 1000 year events etc. At that point it's just a question o

> But a storm surge would be unpredictable, right? No we know what sort of storm surges are 10, 100, 1000 year events etc. At that point it's just a question of what you design the tunnel to withstand. > How do the physics of "crushing" a boat by > raising water level in a confined space work? This is an elementary application of Archimedes' principle. The weight of the ship is equivalent to the weight of the water it displaces[1]. If the ship is stuck against the ceiling of a confined space the pressure it's excreting on the ceiling is going to be the equivalent to the displacement of that "extra" water. 1. Leaving aside the full calculation which takes the difference in the weight of air & water into account for the purposes of this explanation.