About 15 years ago I "arm twisted" the folks at Sandy Point State Park to include a hand launch area (which, at least when I last saw it) allowed you to drive you boat and trailer to the water and put it in.
The wind off the park is great until about 7 p.m. in the Summertime; then generally you have to paddle yourself home. My suggestion, start early, finish early.
Any other questions, let me know. I too used to sail a H-16 from Bethesda, Silver Spring, and Columbia.
Paul