This past fall TISIRI divers Joe Kistel and Ed Kalakauskis were offshore Jacksonville collecting imagery for an ongoing production effort. While filming the sunken vessel below there came a moment when all of the sudden everything became dark. When the divers looked up they found a massive school of Atlantic spadefish blocking the available sunlight. Cameraman Kistel tried to capture some of the encounter and the massive "tornado" shape the school of spadefish created.
The news segment below explains the encounter in more detail and includes footage of the incident.
Below is the actual footage captured: