The whole area there is a bombing and strafing area. It is still used for dog fights and jets running around breaking the sound barrier, but the bombing seems to have stopped in the last 10 years. They mainly used wrecks that were there since WWII. As for a 20 foot hole, yes there are a few deep holes, but only one has visible wreckage, and that is a modern shrimp boat and it is all gone but the outriggers and rigging. There could be some wreckage that has been missed, as they mainly used mags, which only get iron, and that probably had none, or very little. Much of that area way to the NE of the Atocha motherload is sand and much is hard bottom with maybe some sand over it. I know the area that they are working now is sand with mud under it. Once you get a few miles North of the Marquesas, it all seems like sand.