Not sure which boat ramp Bill's referring to, since I'm always in the truck and can't explore those spots. But, when I'm running empty back from CA/AZ/NM, I usually run down US-285, then US-90 to Del Rio on my way to Pharr, TX. On the north shore, where US-90 crosses Amistad, there's a gravel area where I park the truck for a break and a visit to the lake. It's a public access point, but the trail to the water is too rugged for anything much bigger than a kayak.
In warm months (that's most months down there), I spend a while skinny-dipping and sitting in the sun. It's not a place for wandering the shore nude, but the terrain provides lots of "dead space" along small coves. I usually pick a spot right below the US-90 bridge. It's too nearly beneath the bridge to be seen by passing motorists, unless you swim a good ways out from shore.
It is in open sight from the train tracks, so I've been seen nude on the rocks by the train crew a few times, if they were paying attention. That's usually a surprise, since the terrain muffles the sound of the train until it's right there. Since I've been surprised by it a couple times, it's now a challenge to myself, to hear the train early enough to turn around and be waving when it comes into view.
And, yes, Jbee, the water is gin-clear! If you visit right after a heavy rain event, it might be a tad cloudy, but most of the time it's very clear. Be aware, the shore and bottom in the area I'm talking about is very steep. Be prepared to go from wading to no-bottom within a step or two!
