Local newscasts are filled with the story of a police officer taking part in a training exercise south of the District of Columbia who disappeared in Pohick Bay. We were told that he is 42. He was not wearing a wet suit and diving apparatus but rather a “dry suit.” This, we are told, might enable him to withstand submersion in the water, which we are told is 62 degrees. The television stories are filled with search boats and helicopters and sweeping scenes of the water. Like most televised accounts these days, one essential element is missing, never mentioned.

How deep is it?