There's a paid parking lot next to Jackson's Brewery. Just walk across the railroad tracks to purchase or pick up tickets and board the steamboat.
Paid parking right next to the boat, across tge R/R tracks. You may get lucky finding a spot on the boulevard but it is tight all day long.
Oh yeah... parking is tight. If you're staying in the French Quarter it's easier to walk. Or park on a nearby surface street.
Parking is in the parking lot before you dock the boat.
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