I imagine there are innumerable hazards to navigation that would keep transfer of people to a ship in the category of 'difficult, not impossible'.
1. Structural integrity of existing pierage. Who knows if what's left will support people.
2. Barging people out to an anchored ship: hard to do because you have to be very slow about it, and if you aren't you run the risk of sinking whatever rescue craft you use to get people out there. You can't use hovercraft either.
To my way of thinking, you put your energy on clearing a path from the Superdome West to the highest and driest location you can find where you can set up another staging area where loved ones can pick up and relocate people for the next month, and temporarily house, treat, and feed the rest. You salvage all of the schoolbuses you can muster for the job and concentrate on SAR to save as many as you can for staging at the Superdome for relocation.
Wonder if they could airlift in some of those pontoon type bridges the military use, or used to use?
They could use those to get people out to dry land, but I am sure they would think of that, and use them if it were possible to get them in...
showing full interview of Harvey jackson..he is so lost..casino building lifted up and moved in tact about 1/2 mile away in MS according to anderson cooper