Flounder are ambush bottom-feeders — they bury in sand or shell hash and wait for bait to drift over. Best water is the channel edges, drop-offs, and creek mouths where current pulls bait off a flat into deeper water. Mayport jetties, Sisters Creek mouth, the ICW at Palm Valley, and the bridge fenders on the Intracoastal all hold them. They don't roam — find the structure, the fish are sitting on it.
Flat brownish body with a pale underside — both eyes on the upper side, mouth twisted to face up. NE FL gets mostly southern flounder; minimum size is 14 inches in Florida, daily bag 5. Look for the camouflaged silhouette on light sand — polarized glasses are essential for spotting them.
Flounder peak in fall, September through November, when fish stage at inlet mouths during their spawn migration to offshore waters. The 'flounder run' is real — concentrate on the jetties and inlet edges in October. Spring brings them back inshore and they spread across the system April through June. Summer slows; winter most have moved offshore. The fall window is dramatically better than any other.
Anchor or drift just up-current of a channel edge or oyster bar. Use a Carolina rig with a 1/4 oz egg sinker, 18 inches of 20 lb fluoro leader, a 2/0 circle hook, and a live finger mullet hooked through the lips. Drag it slow across the bottom. The bite is a slow load — the rod tip bends gradually, not a sharp tap. Wait three full seconds before reeling tight. Set hard, then walk the fish up off the bottom — they often spit if you fight them off the deck of the boat.
Florida fishing regulations change. Always confirm slot, bag limits, and seasons on the official source before you keep anything. See our Licenses & Regulations page or go straight to MyFWC.com.