The Caribbean Reef at the Shedd Aquarium hosts Navy Divers, Petty Officer 1st Class Mike Panek and Petty Officer 1st Class Chad Ernst , as part of Navy Week in Chicago. Thursday, August 16, 2012. | Brian Jackson~Sun-Times

The Caribbean Reef at the Shedd Aquarium hosts Navy Divers, Petty Officer 1st Class Chad Ernst, as part of Navy Week in Chicago. Thursday, August 16, 2012. | Brian Jackson~Sun-Times

A photographer takes picture of Navy Petty Officer 1st Class Chad Ernst, as he dives The Caribbean Reef exhibit at the Shedd Aquarium as part of Navy Week in Chicago. Thursday, August 16, 2012. | Brian Jackson~Sun-Times

Navy Petty Officer 1st Class Chad Ernst, answers questions from the crowd as he dives The Caribbean Reef exhibit at the Shedd Aquarium, as part of Navy Week in Chicago. Thursday, August 16, 2012. | Brian Jackson~Sun-Times