The Georgia and Carolina coast is salt marsh country. Over 700,000 combined acres of spartina grass, tidal creeks, and oyster bars create one of the most productive estuarine systems on the East Coast. Three-quarters of South Carolina's harvested seafood depends on this marsh at some stage of its life. The inshore fishery here is world-class: redfish tailing on flood tides, spotted seatrout on grass flats, tarpon in the sounds, and sheepshead on every dock piling.
Offshore, the Gulf Stream runs 60-80 miles out, feeding a pelagic fishery of mahi, wahoo, yellowfin tuna, and billfish. The continental shelf is broad, over 10,000 square miles off South Carolina alone, with live bottom ledges that hold grouper, snapper, and sea bass. The Charleston Bump, an underwater ridge that deflects the Gulf Stream, creates unique deepwater habitat found nowhere else on the coast.
Why Water Temperature Runs This Fishery
The Gulf Stream's western wall is the primary offshore feature. Where warm Stream water meets cooler shelf water, temperature breaks concentrate bait and pelagics. Mahi follow weed lines that accumulate along these edges. Wahoo cruise the breaks. Yellowfin tuna build through summer into an exceptional fall bite along the shelf edge.
Inshore, the seasonal temperature cycle drives everything. Redfish are tolerant across a wide range, but spotted seatrout shut down on cold fronts below 55°F. Tarpon arrive in late May when water warms past 72°F. Flounder stack in the passes during the fall run as water cools. Sheepshead peak in winter when cold water concentrates them around structure.
The massive estuaries flush nutrient-rich water onto the shelf with every tide. That creates a chlorophyll gradient visible on satellite imagery where productive coastal water meets cleaner offshore water. Bait concentrates along this boundary, and nearshore predators follow.
Species and Seasons
Redfish: The signature inshore species. Year-round across every salt marsh system from Savannah to Myrtle Beach. October flood-tide fishing is legendary. When fall high tides push water over the spartina, reds move onto the flooded grass to feed, tailing in inches of water. Sight-casting to tailing reds on a flood tide is the defining experience of Lowcountry fishing. Bull reds (30+ inches) school in the passes and along the beaches in fall.
Spotted seatrout: The most caught inshore species in the region. Year-round on grass flats, oyster bars, and drop-offs. Trophy gator trout in spring and fall. Winter trout in deeper holes on warm afternoons. They want 65-80°F and drop off fast on cold fronts.
Tarpon: Late May through October. The sounds and inlets from Hilton Head through Charleston hold silver kings that average 80-120 lbs. Not as famous as the Keys tarpon fishery, but serious fish in serious numbers.
King mackerel: Peak October and November when massive schools stack on the beach and nearshore reefs. Spring run also produces. Charleston's king mackerel tournament scene is competitive.
Mahi-mahi: April through June peak on weed lines and temperature breaks along the Gulf Stream. The Stream sits 60-80 miles out, a longer run than Florida but worth it when conditions align.
Wahoo: Spring through fall, with early-season fish averaging 35-50 lbs. Found along temperature breaks and on trolling runs toward the Gulf Stream edge.
Yellowfin tuna: Build through summer into a strong fall bite at the shelf edge and Gulf Stream ledges. Often caught alongside wahoo and mahi on offshore trips.
Live bottom species: Gag grouper, scamp, red snapper, vermilion snapper, and black sea bass on live bottom ledges at named spots like Red Banks, Jack's Bottom, and Santee Banks. These are low-relief natural hardbottom areas with sponges, soft corals, and ledges that create oasis habitat on the otherwise sandy shelf.
Wreckfish: Unique deepwater species found on the Charleston Bump at 300-2,000 feet. The Bump is an underwater ridge that deflects the Gulf Stream and creates deep habitat found nowhere else on the Southeast coast. Heavy tackle, deep-drop fishing.
Sheepshead, black drum, flounder: Year-round structure and bottom fish. Sheepshead peak in winter on pilings and docks. Black drum in the passes during spring. Flounder in the creeks and inlets, with the fall run in October and November concentrating fish in the passes.
The Spots You're Looking For
The ACE Basin (Ashepoo, Combahee, Edisto rivers) is one of the largest undeveloped estuarine systems on the East Coast. Massive redfish and trout habitat. Winyah Bay near Georgetown is another major estuary with similar species. The entire Lowcountry from Beaufort to Charleston is tidal creek heaven.
Offshore, live bottom ledges at 45-70 feet hold grouper, snapper, and sea bass on structure with 4-6 feet of relief. Named spots like Indigo and Anchor reefs are well-known to the charter fleet. Further out, the Gulf Stream ledges and the Charleston Bump produce pelagics and deep-drop species.
South Carolina maintains 45 artificial reef sites with deployed ships, tanks, aircraft, and subway cars. Charleston wrecks at 60-90 feet hold sponges, soft corals, and a solid spearfishing and dive scene.
Diving and Spearfishing
The artificial reef program gives divers access to wrecks at 60-90 feet with growing marine communities. Live bottom ledges with natural sponge and soft coral cover provide a different underwater landscape. Visibility is the variable. Tidal flushing and river discharge create murky conditions nearshore, especially after rain. Chlorophyll imagery shows where clean water sits vs. river plume.
Spearfishing targets include sheepshead, black sea bass, flounder, and various snapper species on structure. The live bottom areas produce grouper and scamp for divers willing to work deeper structure.
What Chlorophyll Tells You Here
The major estuaries (ACE Basin, Winyah Bay, Savannah River) flush nutrient-rich water onto the shelf. Chlorophyll imagery shows where those plumes are creating productivity. The edge of the plume, where green estuary-influenced water meets cleaner shelf water, concentrates bait and predators.
For offshore trips, SST shows the Gulf Stream position and temperature breaks along the western wall. Chlorophyll adds the productivity dimension. A temperature break with elevated chlorophyll on the shelf side means the food chain is active. That's where the fishing is.
For divers, chlorophyll is the visibility forecast. Low chlorophyll after a period of calm weather means better vis on the reefs and wrecks. High chlorophyll after rain events means the river discharge is on the shelf and vis will be poor.
Fishing & Diving Calendar
January-March: Winter inshore. Sheepshead peak on structure. Black drum in passes. Trout in deep holes. Offshore limited by weather. Water 50-62°F.
April-May: Spring ramp. Mahi arrive on the Stream. Cobia showing nearshore. Spanish mackerel running. Tarpon arriving late May. Trout and redfish strong. Water 62-74°F.
June-August: Full summer. Tarpon in the sounds. Mahi and wahoo offshore. Red snapper and grouper on live bottom. Redfish on the flats. King mackerel starting. Water 75-84°F.
September-October: Fall peak. Flood-tide redfish in October. King mackerel schooling on the beach. False albacore arrive for fly anglers. Bull reds in the passes. Yellowfin building at the Stream. Flounder run beginning. Water 77-68°F cooling.
November-December: Late fall transition. Kings still running. Flounder run through passes. Sheepshead increasing. Trout moving to winter holes. Offshore winding down. Water 64-55°F.
Fishing nearby waters too? Gulf Stream / Outer Banks and Florida Atlantic are the closest covered regions. See pricing for what a plan covering Georgia / Carolinas costs.