Ah, you have a scow. OSYC totally won't work for you. Besides, unless you belong to another YC you can't expect use privileges from any YC, anywhere.
Texas:
Pleasure Island/Sabine Lake area (south of Beaumont, Bridge City area.). Go over to
www.tcdyc.com and ask who to contact for information
Louisiana:
--Cypremort Point State Park (near New Iberia)
--Grand Isle (I'll furnish you a contact if you're interested in going there.)
--Lake Arthur (Clayton... your camp house is there...?)
--Right there in Baton Rouge is False River, where the Hobies used to sail
--Lake Charles (as Clayton has mentioned.)
MS coast:
--Bay-Waveland Yacht Club (unless you belong to a YC, you can't expect to launch - reciprocal privileges, but you could ask.)
--Long Beach Yacht Club (there is a public ramp in its harbor)
--Your best choice is Biloxi: right next the new Schooner Docks is a rather nice public ramp, with some beach next to it. And it's very protected there in Casino Row. And I do believe they've just dredged off that beach there in the area, so it does drop on off.