Crooks and Liars: The Gulf of Mexico is the primary disposal site for unexploded military munitions -- over 30 million pounds of bombs, projectiles and chemical ordnance. And because records are spotty and incomplete, we don't know exactly where these dumps are...
From a paper presented at the 2007 Offshore Technology Conference in Houston:
This notice also recognizes ordnance as a manmade hazard that may have an adverse effect of proposed well operations... UXO (unexploded ordnance) dump zones also exist off the Atlantic and Pacific coasts... Current technology for deepwater production is making the possibility of Atlantic and Pacific margin exploration more of a reality. This will only increase the need for UXO awareness and viable solutions to their existence in deepwater.