On the east side, try the mouth of British-American Canal, Yellow Bayou and Oyster Bayou.
A falling tide is preferable, but I've also caught blues and channels on a rising tide in these locations.
From Point Chevreuil eastward toward the Calumet spillway, try the mouth of Big Beach and Little Beach.
On the east side of Belle Isle, you also can hit the mouth of Big Lacassine Bayou in Little Bay, as well as any of the bayous in East Bay near the Atchafalya River.
Don't limit yourself to the mouths of these outlets. Traveling and setting on anchor a few reaches up any of these navigable bayous and canals will also produce fish.
You might be surprised to find you catch more channel catfish as a result.