the one at pirates cove is usable, as is dora. The one east of 105 had 5-10 yards of dirt before you got to water last time I was down there (about a 2 weeks ago) and the water hasn't come up more than about 3" since then.
So you could probably launch a jon boat there, but I'd say you have a good chance of having your tires sink and needing a tow to get your truck back.