In response to boleybill
The Bienvenue locks appeared to be open the other day, but you’re dealing with construction of the levees. So it depends if they are running trucks across on that day. I would suggest one of two things if you are determined to get on the other side. Launch from Seabrook or the Chef Pass. I am not sure of Seabrook’s accessibility or the condition of the Almonaster bridge which you would have to underpass.
Hope this helps.