So here's the deal. The Port of New Orleans does not provide luggage storage at either of its terminals, but there is a company there who does offer several services that may interest you. Their name is Advance Check-In and their web site is http://www.advancecheckin.com/. Their telephone number, which is also on the site, is 504-471-0080. I called and asked about their services and here is what I was told:
1) When you get off the ship you can give them your luggage and they will deliver it to their office in the baggage claim area at the New Orleans airport. They will give you a claim check and you can pick up your luggage there within two hours of your flight. The cost for this service is $40, which seems high, but it actually is for 1-4 pieces of luggage.
2) You can leave the luggage with them and pick it up after the parade at a cost of $25, again for 1-4 pieces of luggage.
3) They have transportation to the airport through a partner company for $15 per person that leaves from the French Quarter. That is much less than you pay for a taxi.
In summary you can pay $40 to store your bag and have a ride to the airport, or pay $55 to have your bag taken to the airport and have a ride, or pull your bag to the parade route and then either spend the $15 for their transportation or take a taxi. One other caveat. When I called Advance Check-In I spoke with a woman named Angela and told her I had a friend from Seattle (we're all friends on the Forum, right?) who had your situation and asked if she could help you. In the end, because you only have one bag she said if you contact her personally to make the arrangements she would do the airport valet service for $30, so you could do that and take the ride out there for $45. If you want to do this I'd call her soon and remind her that she talked with Jim in NO about you. I don't know your financial situation or how important the luggage storage thing is to you, but if you can afford it the $45 deal looks pretty good. One other possibility. The hotel at the end of the parade route is the Hilton Riverfront. If you happen to be a Hilton Hhonors member, or even better a Diamond VIP member, I'd imagine the concierge there would store your bag for a few hours for a nominal tip. If you are a member of another hotel rewards program you might check to see if one of them is in the area as well. Hope this helps. Please let me know if I can help in any other way.
Jim