I'd like to know if such a source exists, too. There are apparently records of shipping in and out of the port of Bayou St. John (the way to New Orleans from Lake P.) dating to the early 1800s. I encountered references to them in the book 'St. Tammany Parish - L'Autre Cote du Lac' by Frederick Ellis. Where those records may be found and viewed, I don't know.
My ancestor Uriah Smith was an early resident of St. Tammany (1770s) and apparently ran a sloop back and forth from what's now Mandeville to New Orleans on a fairly regular basis in 1804, according to those Port of Bayou St John records mentioned by Mr. Ellis.