Christmas Bay (Brazoria County) Bombing Targets

For decades there were "The Pilings" in Christmas Bay in Brazoria County, Texas.These were a favorite fishing spot, and camp houses were eventually even built on some of them.I have been told that the pilings were put there during World War II for bombing practice.Thus, I'd assume there were targets built over the pilings.
I was told that planes would only drop sandbags as they passed over the targets, not real bombs.Thus, I wonder if they were actually targets (bullseye-type targets???) for practice to drop torpedoes (otherwise, why swoop down to pass over the targets to drop things on them?).Anyhow, Christmas Bay is just down the coast from what was Camp Wallace.Was there some sort of a connection between the two places?What branch of the services used Camp Wallace?Did planes take off and land there?Were the planes that "bombed" the pilings from Camp Wallace?Were real bombs or torpedoes ever used there?