A number of wrecks sit in fairly deep water near the US/Mexican Border, including four destroyers and a structure known as the Missile Tower which is believed to have been used in the test launching of submarine-based missiles.
The 314-foot Hogan is the only wreck in this area which is serviced by San Diego's commercial dive boat operators. She is a WWII-era destroyer, intentionally sunk in November, 1945, during bombing tests. She sits in water approximately 130' deep, and is at 32 31.74, 117 12.57. Dive safely!
The Missile Tower was used by the US Navy to test launch Trident submarine-based missiles. It was floated at the surface, where they would test fire a missile while filming the break-away cover with many very high-speed cameras. As reported by a local technical diver, it "is a large object, about 60' high when it was upright, and 25' on the sides. Rectangular. In the middle is a large tube, 10' in diameter, that goes about 20' into the structure from the top. There are two much smaller tubes over on one side. A catwalk goes around the top of the structure. The whole thing is in pretty good shape, doesn't look like it has been down all that long, but that can also be due to the depth. The top of the thing (it's laying on it's side) is at 140', while the bottom is at 165'. It is covered with large metridium anemones, literally by the thousands."
When the Navy was done with the Missile Tower, the State of California convinced the Navy to let them have it to sink it as an artificial reef, which they did in 1993.
Shown below is the Missile Tower just before sinking. Photo courtesy of the California Artificial Reef Program.