I noticed that no one has responded, so here's what I know, although it's very dated. I've not lived in the
New Orleans area for quite some time, but I'm from there.
I kept a 30' sailboat in Mandeville, pre-Katrina. I know many would move
boats from
New Orleans to the Northshore, either up the Tchefuncte River in Madisonville or up one of the Bayous around Mandeville and Lacombe, such as Bayou Castine. Keep in mind storm surge, it can be significant even on Pontchartrain and the Northshore.
Others hauled their boats, or moved them out of harm's way, some going to Vermilion Bay, south of Lafayette. It all depends on the models predicting the storms path. The important thing is to get familiar with some of these areas and have an exit strategy. Also, ask around your marina or the Yacht Club those that have been there for years to see what their plans are. If they've been there for any length of time, they have a plan.