The AP reports that the army completed a demonstration project to remove underwater unexploded ordnance from “ordnance reef” off the Wai’anae coast using unmanned underwater vehicles:
The Army said Friday it recovered 74 pieces of decades-old exploded ordnance from the ocean floor off Oahu’s Waianae coast during a three-week effort to clear out most of the munitions the military dumped in the area years ago.
The cleanup also recovered 2,300 small arms munitions, U.S. Army Garrison Hawaii said in a news release.
The Army left alone munitions so encrusted with coral that removing them would have damaged the reef. Using a remote controlled robot, the cleanup team attempted to recover more than 150 small, medium and large items that appeared to be weapons. It got 80 of these, but six turned out to not be munitions.
It destroyed more than 330 pounds of explosives, 135 pounds of propellant, and all of the small arms munitions recovered.